Is the ground wire necessary? The appliance will operate normally without the ground wire because it is not a part of the conducting path which supplies electricity to the appliance. If the case is grounded, a high current should flow in the appliance ground wire and trip the breaker.
Also know, why do you need a grounded outlet?
The idea behind grounding is to protect the people who use metal-encased appliances from electric shock. The casing is connected directly to the ground prong. With the case grounded, the electricity from the hot wire flows straight to ground, and this trips the breaker in the breaker box.
Do you need a ground wire for a light switch?
If you are replacing a switch a ground is not required, as per the above exception. However, if you're installing a switch; replacement or otherwise, into a metal box that is grounded. The switch will be ground via the devices yoke and mounting screws. So if the metal box is grounded, the switch is also grounded.
What will happens if we connect neutral to ground?
A second problem with connecting the ground to the neutral happens if your neutral wire breaks between the outlet and your service entrance. Given a ground to neutral connection, this will cause the chassis of your device to be at the "hot" voltage, which is very dangerous.