The entryway thermostat is an "Electromode Model M7-D double line break" with a huge bimetallic strip. At random intervals, a kind of screeching/hissing sound comes from it. (At least, I think that's where it comes from. It never happens when I'm right near it.) I pulled the double breaker than powers the baseboards, and turned the thermostat built into the wall heater all the way down. So there shouldn't be any current flowing, right? So where does the noise come from, and can I do anything about it w/o cutting wires?