Why Your Lights Are Flickering
Flickering lights can be annoying, but they can also signal a deeper electrical issue. While some causes are simple — like a loose bulb — others involve wiring faults or overloaded circuits that require immediate attention.
1. Loose or Failing Light Bulb
The most common cause of flickering is a loose bulb. Over time, vibration or heat can cause bulbs to loosen slightly, breaking the electrical connection.
If the light won’t turn on at all, see light won’t turn on.
2. Loose Wiring in the Fixture or Switch
Loose wiring creates intermittent contact, causing lights to flicker when the circuit is disturbed. This can happen inside the light fixture, switch box, or junction box.
Learn more in loose wiring symptoms.
3. Overloaded Circuit
If lights flicker when appliances like microwaves, space heaters, or AC units turn on, the circuit may be overloaded. This is especially common in older homes with limited circuits.
For more overload indicators, see overloaded circuit symptoms.
4. Faulty Light Switch
A worn or failing switch can cause flickering, especially if the switch feels loose, crackles, or doesn’t “click” firmly. Switches wear out over time and may need replacement.
For related issues, see switch not working.
5. Voltage Fluctuations
Sudden dips or spikes in voltage can cause lights to flicker. This may be caused by large appliances cycling on, utility company issues, or wiring problems inside the home.
6. Loose Service Connection
If multiple lights flicker throughout the home, the issue may be at the meter, service mast, or utility connection. This is a serious condition that requires professional attention.
7. Faulty Fixture or LED Driver
LED lights often flicker when their internal driver begins to fail. Older fluorescent fixtures may flicker due to worn ballasts or aging tubes.
When Flickering Becomes Dangerous
Stop troubleshooting and call an electrician if you notice:
- Flickering across multiple rooms
- Burning smells or warm switches
- Buzzing or crackling sounds
- Flickering that gets worse over time
When to Call an Electrician
If tightening the bulb and checking the switch doesn’t solve the issue, the flickering may be caused by wiring faults or voltage problems. A licensed electrician can diagnose the source and ensure the system is safe.
Helpful Resources
- Symptoms Index – Quickly find your electrical issue.
- FAQ – Answers to common electrical troubleshooting questions.
- Electrical Safety Foundation International – Trusted electrical safety information.