The lights seem to dim when we plug anything into the bottom part of the outlet in the kitchen. Wondering why this could be happening?
First possibility, a bad receptacle or bad wiring connections to the receptacle. Deal with that fast -- it burns down houses.   

Builders often use the cheap 60-cent receptacles, and they are also fond of using "back stab" connections to those receptacles which are terrible.  Replace with a $4-tier receptacle which has side screws or screw-and-clamp.