Does it work to find short circuits on outlets and light fixtures? In order words it's a wire tracer as well as breaker finder?

The ET310 is not designed to function as a wire tracer, it is designed to locate the correct circuit breaker in a panel to which an electrical outlet or fixture is connected. The transmitter is connected to the electrical outlet or fixture in the circuit while the receiver is used to scan the breakers in the circuit breaker panel. The transmitter can be connected to the alligator clips adapter for use on bare wires and connected to the light socket adapter to find the correct circuit for lighting.