Last night I had a double-tapped breaker fail. Turns out the former owner put most of the overhead lighting, and the living room outlets, on these two taps.
It's a Cutler-Hammer box so the double-tap was legal.
The basement overheads started flickering as I was working, and soon went out. When I got to the panel, I could smell something was wrong, so I started feeling breakers for heat. Found a warm one that sizzled when I touched it.
Luckily I had purchased a tandem breaker (two separate circuits that fits in a single breaker slot) back when I took possession of the house.
Is there a limit on how many tandem breakers can be installed in a breaker panel? There are two now, and at least one other double-tapped circuit in the house.