Short version: We had low and possibly fluctuating voltage on one circuit in my house. 4 wall plugs and ceiling fan with light kit. Around 90 volts.
Long version: Entertainment center has Ring alarm base station, TV, Denon AVR, XBox, AppleTV all plugged into one surge suppressor which is plugged into a wall outlet. My wife showed me her phone yesterday morning and she had 130 alerts from Ring of power loss and power restored. I turned on the TV (Dish, TV, Denon all come on) and TV immediately rebooted, the Denon seemed to be rebooting, and the Dish Hopper rebooted.
Turns out that same circuit had the ceiling fan and fan light on the circuit. These were controlled by a Lutron Caseta fan controller and a separate Caseta switch for the fan light. Those switches were installed during a small remodel and have been working for 3 or 4 months with no issues. But my wife noticed the small LED lights on the switches were flashing. I immediately suspected them and uninstalled them by removing their pigtails from their respective wire nuts in the wall box.
When I did this, it dropped the downline voltage (4 wall outlets downstream) to 11vac.
My wife later told me that she had previously plugged in her old Kirby Vacuum cleaner to the female side of the Christmas light string plugged into the first downstream outlet from the light switches that I opened up. A major load, for sure.
When looking at my Circuit Breaker chart, I noticed a note I had made a long time ago that to turn off the Pantry light, one had to flip circuit breaker #8 and #20 simultaneously. Never had this addressed by an electrician.
Turns out the circuit in question is c/b #20. But the pantry lights no longer work now.
So I've turned off #8 and #20 while waiting on an electrician. Would be easier to trace if this wasn't a two story house. 99% sure all the wiring to this problem is routed through the ceiling/under upstairs floor.
Any ideas? ("Sell the place" is taken, we've already put it on the market.) Thanks. Merry merry.