The earthing of electrical appliances is done as a safety measure. Most of the non-current-carrying metallic parts of an electrical appliance are well insulated and safe to use, but in a faulty appliance current can pass through even these insulated parts and pose a risk to the life of the user. This is because the human body allows an easy flow of electricity through itself to ground. The earthing of the appliances prevents this risk as the earth wire offers a still easier path compared to the human body to the flow of leaking current to ground, thus making the appliance safe to use.
