The lights in one section of my house will flicker sometimes and then go out. They will stay off for several hours and then the power will come back again. It is only the lights, as the power outlets in all of the affected rooms still work fine (night light in the bathroom is still on, the laundry machine still works, etc.). I checked the circuit breaker and none of them were tripped. I tried resetting them, but that didn't work. In the past, the lights would go off for several hours and then turn on by itself, with no action on my part. This time, the lights have been off for 2 days and have not come back on. Any ideas on what's going on?