Written by Roger F. Shumake, licensed electrician and owner of Electrician Burbank CA. Serving California homeowners since 2015.

Flickering lights are one of the most common electrical concerns homeowners face. Sometimes it’s a simple fix like a loose bulb. Other times, it signals a serious electrical issue that needs immediate attention. Understanding the difference between harmless flicker and dangerous wiring problems can help keep your home safe and well-lit.

The good news? Most flickering light issues have straightforward causes. Whether it’s a light bulb that isn’t screwed in securely, voltage fluctuations from appliances, or loose wiring behind a switch, identifying the source is the first step toward fixing the problem.

Are Flickering Lights Normal or a Sign of a Problem?

Not all flicker means danger. Brief, occasional dimming when your AC kicks on is usually normal. But constant flickering, lights that suddenly start flickering across multiple rooms, or bulbs that flicker along with warm switches are warning signs you shouldn’t ignore.

Here’s how to tell the difference:

Brief vs. constant flicker: A momentary dim when large appliances start is typically harmless. Lights that flicker continuously suggest loose connections or circuit overload.

One room vs. whole house: If lights are flickering in just one room, the issue is likely isolated to that circuit or fixture. Flickering throughout your home points to problems at your electrical panel or with the utility company.

New bulbs vs. old wiring: LED bulbs paired with old dimmer switches often flicker. But if standard bulbs flicker in multiple fixtures, your home’s electrical system may need attention.

Weather-related vs. random: Flicker during storms from lightning strikes or grid issues is expected. Random flickering on clear days deserves investigation.

Common Reasons Your Lights Flicker (Electrician Explained)

Loose Light Bulbs or Fixtures

This is the simplest cause of flickering light bulb issues. When a bulb isn’t screwed tightly into its socket, the electrical connection becomes intermittent. The light will flicker or dim as the contact shifts.

The fix: Turn off the power and tighten the bulb. If it’s already secure, check that it’s compatible with the fixture. Some LED lights don’t work well in enclosed fixtures or with certain dimmer switches.

Voltage Fluctuations from Appliances

Large electrical devices draw significant power when they start. Air conditioners, refrigerators, and microwaves can cause brief voltage drops that make other lights in your house flicker momentarily.

This is especially common in older homes where circuits are shared between lighting and appliances. The sudden demand creates a temporary fluctuation in the electrical current.

When it’s normal: Brief dimming that lasts less than a second when the AC turns on.

When to worry: If lights dim significantly or stay dim, your circuit may be overloaded or your panel undersized for your home’s electrical needs.

Loose Wiring or Connections

This is a potential fire hazard. Wiring can loosen over time due to thermal expansion, poor installation, or simple wear. Loose connections generate heat and arcing, both of which pose serious risks.

Where it happens:

• Behind light switches
• Inside light fixtures
• At junction boxes
• In your electrical panel

If you notice flickering paired with warm switches, buzzing sounds, or a burning smell, turn off the breaker to that circuit and call a licensed electrician immediately.

Failing Light Switches or Dimmers

Switches wear out. The internal contacts that complete the circuit can corrode or become loose. When this happens, the connection becomes inconsistent, causing the light to flicker.

Dimmer-specific issues: Not all dimmers work with LED bulbs. Using incompatible dimmer switches with LEDs causes flickering or buzzing. You need compatible dimmer switches designed for the type of bulb you’re using.

Circuit Overloads

Every circuit in your home has a maximum safe capacity. When too many electrical devices run simultaneously on one circuit, it can cause lights to flicker as the system struggles to distribute power.

Common scenarios:

• Running a space heater and vacuum on the same circuit
• Too many devices plugged into one room
• Older panels with limited circuits
• Shared circuits between lighting and outlets

An overload doesn’t always trip the breaker immediately, but it stresses your wiring and creates fire risk over time.

Electrical Panel or Breaker Issues

Your electrical panel is the heart of your home’s electrical system. As it ages, breakers can malfunction, connections can corrode, and the panel itself may become inadequate for modern power demands.

Warning signs:

• Breakers that trip frequently
• Rust or corrosion inside the panel
• Flickering that affects multiple circuits
• A panel over 25 years old

California homes built before the 1990s often have undersized panels (100-amp service) that struggle with today’s electrical load from multiple devices, appliances, and home lighting systems.

Utility Company or Grid Issues

Sometimes the cause of your flickering lights isn’t inside your home at all. Problems with transformers, neighborhood-wide voltage issues, or grid fluctuations can affect everyone on your street.

How to check: Ask your neighbors if their lights are flickering too. If multiple homes are affected, contact your utility company. They’ll send someone to diagnose and fix the issue safely.

Storm damage and lightning strikes can also cause temporary grid problems that lead to widespread flicker.

Why Lights Flicker More in Older Homes

If you live in an older California home, flickering is more common—and potentially more serious. Here’s why:

Outdated wiring: Homes built 40+ years ago weren’t designed for modern electrical demands. Back then, a home might have had a TV, a few lamps, and basic appliances. Today’s households run computers, smart devices, multiple TVs, and high-draw appliances simultaneously.

Aluminum wiring: Some homes built between 1965 and 1973 used aluminum wiring instead of copper. Aluminum expands and contracts more with temperature changes, leading to loose connections over time. This is a known fire hazard.

Limited circuits: Older homes typically have fewer circuits. When lighting and appliances share the same circuit, voltage fluctuations from one device cause lights to flicker.

Aging panels: A panel installed in the 1970s or 1980s has mechanical components that wear out. Breakers lose their ability to maintain consistent contact, causing intermittent power delivery.

The mismatch between old infrastructure and modern power demand is one of the leading reasons why your lights flicker in older properties.

When Flickering Lights Are Dangerous

Most flicker isn’t an emergency. But certain warning signs indicate underlying electrical problems that could cause electrical fires or equipment damage:

Burning smell: Any odor of burning plastic or hot wires means immediate action. Turn off power at the breaker and call a professional electrician.

Warm switches or outlets: Electrical components should never feel hot. Warmth indicates resistance in the connection—a sign of loose wiring or a faulty light switch.

Buzzing sounds: A buzzing or humming noise from switches, fixtures, or your panel suggests arcing or loose connections.

Flickering across multiple rooms: If lights in your house are all flickering simultaneously, the issue is at your panel or meter, not individual fixtures.

Breakers tripping with flicker: If your circuit breaker trips at the same time lights flicker, you have an overload or short circuit that needs professional diagnosis.

These aren’t scare tactics—they’re real indicators that your home’s electrical system needs attention. Ignoring them can lead to equipment malfunction, potential fire hazards, or costly damage.

Can Flickering Lights Damage Appliances or Electronics?

Yes. Repeated voltage fluctuation stresses sensitive electronics. Computers, smart TVs, medical equipment, and modern appliances all expect stable power. When the voltage isn’t consistent, it can shorten their lifespan or cause immediate failure.

What happens during voltage instability:

• Circuit boards experience thermal stress
• Capacitors wear out faster
• Hard drives and processors are more prone to errors
• Motors in appliances can overheat

Long-term wear: Even if your devices don’t fail immediately, continuous exposure to flickering and voltage swings degrades internal components. This is why surge protection matters—it buffers against sudden changes and extends the life of your electronics.

If you’ve noticed flickering lights along with electronics behaving strangely (computers freezing, TVs resetting), it’s time to call an electrician to diagnose the root cause.

What You Can Check Safely Before Calling an Electrician

Before scheduling a service call, there are a few safe troubleshooting steps you can take:

Tighten bulbs: Turn off the light, wait for the bulb to cool, then ensure it’s screwed in securely. Check that the bulb is the correct type for the fixture and dimmer.

Try another fixture: If one light is flickering, test the bulb in a different socket. If it still flickers, replace the bulb. If it stops, the original fixture or wiring may be the issue.

Note patterns: Write down when flickering happens. Does it occur when specific appliances turn on? Is it constant or intermittent? This information helps your electrician diagnose the problem faster.

Ask neighbors: Especially useful if you suspect a utility issue. Neighborhood-wide flickering points to grid problems, not your home wiring.

Check the connections at the fixture: If you’re comfortable doing so, turn off the breaker, remove the fixture cover, and visually inspect for loose wires. Don’t touch anything—just look. If wires appear disconnected or burned, leave it to a professional.

Check breaker labels: Look at your electrical panel. Are multiple circuits labeled for the same area? This might explain overload issues.

Safety boundaries: Don’t open your electrical panel unless you’re trained. Don’t touch wiring if you’re uncertain. And if anything feels warm, smells burned, or sparks, stop immediately and call an electrician.

When You Should Call an Electrician

Some situations demand professional help. Here’s when it’s time to call a licensed electrician rather than attempt DIY fixes:

Repeated flickering: If lights are still flickering after you’ve tightened bulbs and eliminated simple causes, the issue is deeper in your electrical system.

Whole-house flicker: When lights throughout your home dim or flicker simultaneously, the problem is at your panel, meter, or service line.

Warm electrical components: Switches, outlets, or fixtures that feel warm indicate resistance and potential fire hazards.

Recent remodels: If flickering started after renovation work, new wiring may not be properly connected or your panel may be overloaded by additional circuits.

Panel age concerns: If your electrical panel is over 20 years old and showing signs of wear (rust, frequent breaker trips, burning smell), it’s best to have it inspected.

Persistent flickering after bulb replacement: If you’ve replaced the bulb and it’s still flickering, the socket, wiring, or dimmer switch likely needs attention.

You live in an older home: Properties built before 1980 often have wiring that doesn’t meet current safety standards. A professional electrician can assess whether your system needs an upgrade.

A qualified electrician can diagnose and fix the issue safely. Attempting electrical repairs without training puts you at risk of shock, fire, or making the problem worse.

How an Electrician Diagnoses Flickering Lights

Understanding what to expect during a service call helps you feel confident in the process. Here’s how a professional electrician approaches flickering light issues:

Load testing: We measure the electrical load on each circuit to identify overloads or imbalances. This shows whether you’re drawing too much power through one circuit or if the demand is distributed unevenly.

Circuit inspection: Each circuit connected to the flickering lights gets checked. We test connections at outlets, switches, junction boxes, and fixtures for tightness and integrity.

Panel evaluation: We open your electrical panel and inspect the breakers, bus bars, and wiring connections. Corrosion, loose wires, and worn breakers are common culprits that only become visible during inspection.

Voltage readings: Using specialized meters, we measure voltage at different points in your system. Consistent voltage drop indicates a failing connection. Fluctuating readings point to external issues or appliance interference.

Utility coordination if needed: If testing shows the problem originates outside your home, we contact your utility company. They’ll inspect the transformer, service line, and meter to resolve grid-related causes of flickering.

This methodical approach ensures we find the actual cause—not just treat symptoms. It’s why experienced electricians can often solve problems that homeowners can’t identify on their own.

Frequently Asked Questions About Flickering Lights

Can LED bulbs cause flickering?

Yes. LED lights can flicker when paired with incompatible dimmer switches or when the bulb itself is low quality. LEDs require less power than incandescent bulbs, and older dimmers weren’t designed for this. Switching to compatible dimmer switches designed for LEDs usually solves the problem. Also, cheap LED bulbs may have poor internal drivers that cause flicker even without a dimmer.

Why do lights flicker when the AC turns on?

Your air conditioner draws a large amount of power when it starts. This sudden demand can cause a brief voltage drop in your home’s electrical system, making lights dim momentarily. If the flicker is brief (under a second), it’s typically normal. If lights dim significantly or stay dim, your circuit may be overloaded or your panel undersized for your home’s needs.

Is flickering a fire hazard?

It can be. Flickering caused by loose wiring, faulty connections, or overloaded circuits creates heat and arcing—both of which are potential fire hazards. If flickering is accompanied by warm switches, burning smells, or buzzing sounds, it’s a serious issue. However, flickering from a loose bulb or incompatible dimmer switch isn’t dangerous.

Can a bad breaker cause flickering?

Absolutely. A worn or corroded circuit breaker can’t maintain consistent electrical contact. As the connection intermittently fails, lights on that circuit will flicker. Bad breakers can also overheat, posing a fire risk. If you suspect a breaker issue, have a professional replace it.

Do I need a panel upgrade?

Possibly. If your home has frequent flickering, tripping breakers, or you’re adding new appliances and circuits, your existing panel may be inadequate. Homes with 100-amp service often struggle with modern electrical demands. Upgrading to a 200-amp panel provides capacity for current and future needs. An electrician can evaluate your usage and recommend whether an upgrade is necessary.

Keep Your Lights Steady and Your Home Safe

Flickering lights aren’t always serious, but they’re always worth investigating. A loose light bulb is an easy fix. Loose wiring inside the bulb socket or behind a switch is a potential fire hazard that demands professional attention.

Whether it’s a simple fix like tightening a bulb or a more complex issue like circuit overload or a failing panel, understanding the cause of your flickering helps you make informed decisions. Some problems you can handle yourself. Others need the expertise of a licensed electrician to diagnose and fix the issue safely.

If your lights are still flickering after basic troubleshooting, or if you notice any of the warning signs we’ve covered—warm switches, buzzing sounds, burning smells, or whole-house flicker—it’s time to seek professional help.

Roger F. Shumake and the team at Electrician Burbank CA provide honest inspections and reliable electrical service throughout California. We’ve been helping homeowners solve flickering light issues and maintain safe electrical systems since 2015. If you’re dealing with persistent flickering or have concerns about your home’s wiring, we’re here to help.