When I plug my Bunn coffee pot (which has a reservoir to keep water hot) into the wall outlet an overhead light which I think is on the same circuit gets brighter. The outlet measures 129 volts AC.

You have a potential serious issue, most likely with what is called an open neutral, either a shared neutral for two circuits, or a loose connection in the utility feed neutral.

Stop using any circuit with the high voltage, and get someone to come out and check your system and circuits to eliminate the high voltage.