This worries me but no one else in my family. It is two flood lights over the kitchen peninsula. Each of them does a quick flicker every minute or so. House was built in the 80s. Incandescent bulbs. Very difficult to screw the bulbs in or out because of the annoying trim around them, but I managed to loosen and tighten each one a bit, trying to figure out which was flickering. Both are. I thought maybe one bulb was bad, but both? Or both cannot be screwed in all the way? They feel OK, but I can't really tell because I can't take the trim off without someone noticing, and I have been told to shut up and leave things alone (not my house). Could the problem be at the switch? It's a push dial with a dimmer. I wish I could get someone else to care enough to call an electrician, but so far no.