At least it wasn't the disposal. I never had that problem since I've always lived where I had a septic system and they didn't make disposal systems for septic tanks in the early years. Plus, the only time I ever had a septic system issue was a few years ago when the line fractured. That was the only time I had the tank flushed.
Your electric issue reminds me of the one I had a couple years ago in my garage. The outlet I had my freezer on was dead, I thought, but turned out to be low voltage. It drove me crazy. After troubleshooting, I found the outlet was on the same circuit as my main bathroom GFCI which led me out to my main deck where I found the culprit. When they re-sided my house, they loosened one of the wires on that outlet.
Your electric issue reminds me of the one I had a couple years ago in my garage. The outlet I had my freezer on was dead, I thought, but turned out to be low voltage. It drove me crazy. After troubleshooting, I found the outlet was on the same circuit as my main bathroom GFCI which led me out to my main deck where I found the culprit. When they re-sided my house, they loosened one of the wires on that outlet.