I had a 2 prong plug in place where I needed a 3 prong. (no heavy loads, just TV and such) I read about replacing this with a 3 prong and found out the following:
If the hot end to the box screw registers a voltage, then the metal box in the wall is grounded.
I should use a GFCI outlet if possible in the box.
When I opened the outlet I realized that the box is too small for the GFCI outlet. Instead, I had a self-grounding 3 prong outlet.
I installed the self-grounding outlet, and tested with a circuit tester. The circuit tester lights up normal. However, my contact-less tester beeps on each hole. I also measure the following voltages:
- Hot to Neutral - 120V
- Neutral to Ground - 0V
- Hot to Ground - 120V
Is this normal for a self-grounding outlet?