Mike Dobony wrote:

Get a circuit tracer that plugs into outlets and light adapters and
find the breaker(s) it is hooked up to. I had the same situation and
had one circuit hooked up to 2 breakers in a house I bought. The
only thing that was good about it was that they were on the same
phase. What happened was that instead of 20 amp service to the
outlet I had 40 amp service! I took care of it by capping off the
extra feed wire to the circuit. My guess is that a wall box has 2
feeds for 2 circuits and they are improperly joined in a box
somewhere.

$20.00 at Harbor Freight. Just got one but haven't tried it yet.