This simple circuit constantly monitors the main distribution box and issues an alarm when it is running. It can sense the high temperature caused by overheating and help prevent any disasters caused by sparks. Due to a short circuit in the power supply box. It also automatically switches a bright white LED etc. The LED provides ample light to check the wires or fuses of the power box in the dark. There will be a beep when the circuit is powered off, and beep when the power supply is restored.