converting 2 prong outlets to 3 prong

I recently bought a home that was built in 1952. It is a one story home, with an unfinished basement, and has an accessible attic. The outlets in the kitchen and the bathroom have been updated to grounded GFCI outlets, which is great. However, my living room and 3 bedrooms have not been updated. I am having a difficult time trying to decide on what approach to take to replace my 2 prong receptacles with 3 prong ones, without having to hire an electrician. Here's my dilemma. All of the outlet boxes in question are plastic boxes. The wiring is an old wire that is non-metal with only two wires coming from it, a black one and a yellow. Hence, there are no ground wires. The odd thing is that in one of the bedrooms, two of the outlets were 3 prong outlets. When I opened them up to see how they were grounded, the previous owner simply took a copper wire and connected it from the green ground screw on the new 3 prong receptacle to the to the bottom neutral screw on the same new receptacle. In any case, my outlet tester reads that this is correctly done. I'm not an expert, but having two wires connected to that neutral, silver, screw does not seem legal to me. Also, one outlet in my living room, which has my 50 inch plasma connected to it, also creates a problem. When I simply changed the 2 prong receptacle to a 3 prong receptacle without having anything connected to the green ground screw, to my surprise, it reads that it is grounded. I'm assuming that the plastic box is somehow grounded either to the service panel or to a metal water pipe downstairs. Should I leave that one alone? The only thing I could think of doing is just trying to take new wire with a ground and stick them up into the holes from the basement where the old wires already are and hope that they will pop up where the outlets in question are. The second thing I thought about doing but wasn't sure about was connecting a copper wire from the service panel to each of the green screws on the new receptacles. And lastly, I thought about changing the plastic outlet boxes to metal boxes and then simply grounding the receptacles to the metal box? I'm not sure if one or any of these are the correct way of going about this. Please someone help. Thank you.

 

First of all it is never legal or safe to connect the ground to neutral at an outlet. You should replace them with non grounded outlets or remove the jumper.

You have a number of choices. Most equipment you would normally use in a bedroom location would not have a ground pin but some do.

The only real answer is to rewire if you must have a ground and depending on the construction this might not be easy.

You do have the option of using a GFCI breaker on the non grounded circuit. GFCI's protect for faults to ground but they do not require a ground to work. This would give you a good deal of protection on the ungrounded circuits but you still would not have an actual ground. You could also use an AFCI which is a requirement for bedrooms in new construction for added protection from arc faults. I say use a breaker because it would be easier to do. Otherwise you would have to trace the circuit to put the outlet as the first device or put GFCI's at every outlet position which would cost more than the breaker option.

I too live in an old house and I have a few bedroom circuits that are not grounded. I really do not see this as a problem and I have no burning desire to go through the extensive work to change it.