The 2 overhead lights in my garage are controlled by LIGHTED 3way switches. The wiring has been in place and operating properly for years. Recently, ONE of the lights has been going off and on at various times for various length of time. Only 1 light has been effected, the other has been fine. I've made the following changes in this order: replaced the bulb, replace the light fixture and replaced the switch closests to the problem light. I have not been able to correct the problem. Could the 2nd swicth be the problem? What causes switches to suddenly fail? Any help would be appreciated!
With only 1 light having a problem it is not the switch. You changed the lamps. Since it still has a problem the ballast in that fixture is failing. This is very common with electronic ballasts. When the lamps get old they stress the electronics. The lamps need to be changed as soon as they start flickering especially with black at the ends of the tubes. You will need to replace the ballast or the fixture. Some times cheaper to replace the fixture, or buy a cheap fixture of the same size and swap the ballast if it is an expensive fixture.