Two of the four overhead lights had potential safety issues from corrosion found in the wire nut connections and the overheating of a wire connection on the 3 way switch that have have become hot enough to cause the insulation to flake off and operated from dim to bright depending on how you operate the switches.
I removed the wire nuts, cut the corrosion off, re-twisted them together and soldered them together, reapplied a new yellow wire nut and taped it in place with electrical tape so now all six bulbs will light when switch turned on.
I also have replaced the overhead bulbs with 1156 LED bulbs that operate much cooler and should never burn out.
I also ran in incoming hot wire to a 120v commercial switch with a shallow box I found at Home Depot so I now have switch mounted in plastic that is much heavier duty.
This light in bath room.
This light over the couch/eating area.
Both have the LED 1156 bulbs I got off ebay.