Could not find a problem. This is in a rental I own. Has a 3 light fixture above sink. Switch and light maybe 12 years old.
Tenant turned on light all 3 bulbs blew with black spots on the bulb, and there was a pop at the switch.
What could cause this. When I got there I installed 3 new bulbs to try and duplicate but everything worked fine.
But went ahead and inspected the switch, removed and inspected the fixture. Everything looked great. No loose connections or black/burnt spots on any wiring, voltage good.
Went ahead and replaced the switch but really just to do something. Had the switch out and had a spare with me so figured why not and they are cheap.
So everything works fine now. But I would have preferred to actually see a problem and know I corrected it.
I can understand if it was just a bad bulb going out. And bulbs were about 5 years old. But three at the same time.

Thanks for any suggestions.