I have two-prong outlet(old outlet) and like to change to grounding three-prong outlet. Since I have a lot of appliance that require three-prong outlet. I know I can use connector to covert to three-prong. I would rather change the power outlet. I got a three-prong grounding outlet from Home Depot. Some people say that I can just wire the third wire to the metal box and the grounding outlet, but some people consider I should not do that it is not safe.
Should I just wire the third wire, connect between metal box and the three-prong grounding outlet?