How to detect household circuit faults with electronic probes

Electronic probe is an effective tool to check the circuit. The correct way to use the electric probe is to touch the metal cap or button on the back of the pen holder (the liquid crystal electric probe is a conductive rubber button) and touch the circuit to be tested with the test end. Before formal use, the live part should be tested to confirm that the electric probe is intact. When the circuit is normal, it should be that the live wire has electricity (bright) and the ground wire has no electricity (not bright). Both lines are not bright, indicating that at least the fire line is broken; Both lines are on, indicating that the ground wire is broken.