I see circuit tracers priced from $25 to 1000s of dollars. I guess that the cheap ones won't do. I can find the circuit breaker. I want to find where the NM cables run inside the walls and perhaps ceilings, so that I have some hope of finding where it is mis-wired. So all I need is a tracer that can detect the cable (either energized or not) through a layer of 1/2" drywall up to 4" deep in the wall.