Doing some work on a house that has some can lights with either rectangular or square “dirt” patches. There isn’t access to them, but they are in a fairly recent room addition (10-12 yrs ago maybe), with only a roof above them. I think it is insulated with fiberglass batts, but not totally sure. Probably only a couple of feet from top of can lights to the roof.
It’s not where someone forgot to paint.
I was thinking maybe it was an electrostatic build up of dirt caused by the power in the can lights? Anybody know what the cause of this is and what can be done about it?