How can you relay if a wall outlet is grounded?
Answers: Great question. Lots of wrong answers. A three prong receptacle can be installed contained by a box with no ground present. So looking at it from the outside won't relay you that it is grounded. A bootleg jumper line from the neutral screw to the ground screw will fool the worthless testers the others are raving around. So that won't tell you any. I would pull it out and look for a ground chain on the ground screw. Then I would check the voltage between the hot wire and the ground for source voltage. If no ground line was near, and it was contained by a metal box, I would measure voltage between the hot cable and the box to make sure I have the source voltage. Those 2 things would tell you if the outlet is grounded.
If it is a 3-prong outlet.
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