OK, I said I'd post back with an update. As luck would have it, before I
changed out the backstabbed outlets, the overhead light burned out in the
suspect room. When I went to change it, the glass was broken away from the
metal. I got pliars and got the old one out and replaced it with new and the
dimming has stopped for now. I don't know if that's it, but I'm not going
any further until it starts again. Anyone know if and why a damaged light
bulb could have caused my problems?