Identify breakers and ferret out faults without cutting power to critical systems. More versatile than a breaker finder, circuit tracers track the path of an entire energized or de-energized circuit’s wiring through walls, ceilings, and floors. They’ll even detect wires underground without being blocked by conduit or cement.

Each tracer kit includes a transmitter and a wireless receiver. Plug the transmitter’s leads into an outlet or connect its alligator clips to bare conductors to send a signal through the circuit you want to trace. Then, move the receiver against the wall like a stud finder to follow the signal’s path and detect the circuit’s wiring. Boost the receiver’s sensitivity if the signal strength drops as you move away from the transmitter, or dial it down to eliminate false positives from nearby circuits. Keeping the sensitivity low is also useful when you need to single out a specific wire within a bundle.