Problem fixed now.
Synopsis:
I started to power down and unplug stuff last night (including this PC) and noticed even more dimming and pulsing of lights. I checked the voltage again at an outlet that I had previously saw as 120 a hour earlier and it was now showing 130. I went in high gear and switched off the main breaker. This was not ideal as the temperature was dropping into the teens and without power my boiler doesn't work

but I took the previous warnings is saw in this forum to heart and did not want to take chances.
I call the electrician and power company first thing this morning. The electrician got here first. He checked the panel and everything looked OK. He then went outside and discovered a loose neutral connection on the main line to the house. This loose connection was actually inside an expansion box that his partner put in a few years ago

.
He replaced that connection and everything was good as new.