An earth wire's purpose is to protect against electric shock by providing a path for current that would otherwise run through a person or to protect against potential damage by limiting the amount of voltage that can surge in a device. An earth wire serves as one of the conductors in some applications, such as telegraphy. The metal body of an electrical item is earthed to prevent electric shocks. Earthing refers to the use of an earth wire to connect the metal case of electrical appliances to the ground at zero voltage. There are three wires in a household circuit: a live wire, a neutral wire, and an earth wire. The earth wire has one end buried in the ground. Using a three-pin plug, we connect the earth wire to the metal casing of electrical appliances.