Flickering lights are a common problem that can have a variety of explanations. They aren't always a sign of a serious electrical issue that warrants professional help. Here are four ways to determine where the problem is coming from and whether or not you'll need an expert to fix it.
Loose Light Bulb
If only one light is flickering the issue is probably the bulb itself. Unscrew the bulb completely, and then screw it back in. Make sure you turn off the switch first. If the bulb continues to flicker, try a different bulb. If the other bulb doesn't flicker, the original bulb is either faulty or has surpassed its lifespan.
When the above technique doesn't work, investigate the actual switch. Turn it off and on a few times to see if the flickering dies down. If it continues, try a different outlet. Sometimes loose screw terminals can cause a bad connection. Check the socket casing to see if it's loose or snugly in place. Tighten the screw terminals if needs be. Any other problems with the outlet should be addressed by a professional electrician.
When all of the lights in a particular room are flickering, you may have a bigger problem to contend with. If the weather is bad, simply turn off the outlets and wait for it to change. If the problem continues, it could mean that your lights are sharing a branch circuit with another appliance. This often causes light bulbs to shine brighter than usual or burn out too quickly. Keep a watchful eye on your other appliances. For example, when the lights are flickering you might notice problems with the temperature of your fridge or freezer as well.
Temporary Light Flickering
If your lights flicker when you initially turn them on, but fully illuminate after a few seconds, you're probably using a fluorescent bulb. This is perfectly normal. Many energy saving bulbs will also take a few minutes to fully light up and may flicker when they're initially switched on. Sometimes the lack of brightness may even cause your mind to play tricks on you, giving the illusion of flickering when they're just getting brighter.
If you're still not sure what's causing the problem, don't take any chances. Tampering with electrical equipment can be very dangerous if you don't have the knowledge or safety equipment. To resolve more serious issues always consult a commercial electrician.