Originally Posted by bud16415
Sometimes older wiring or some electricians seemed to really scrimp on the wire length. Some of the older boxes were not as deep and the kept the wires short making them harder to work on. You have two blacks and two whites that means one black and white are feeding the box from someplace (could be another outlet) and the other pair is going off to feed something else. The bare wires are the ground the white is the common and the black is hot. The ground wires should be joined together in a way that connects them both to the box and also that green screw on the outlet. That green screw goes internally to the bigger round ground prong hole in the outlet.
Sounds like the outlet isnt grounded at this point but you have wires in there to try grounding it with. If thats the case you are using it now without a ground and the noise isnt a ground loop of any kind I described.
After turning off the power and if you are going to take it apart to get in there and work figure out what black wire is the power to the box and mark it for future reference. You might have to take the wires off powered down and then carefully have them apart turn the power on and check with your meter for the hot black wire. Then shut the power back off. There should be a clamp in the back holding the wires and you may be able to get a little more length if you loosen that clamp. The ground wire and the common should be the same potential with the hot black wire when testing. Get a piece of green or bare wire and fix the grounds up like they are supposed to be and give it a try again.
ok i went for another look and yes i have 2 seperate sets of wires. not sure what it would be feeding, this is the only outlet in the room.
the grounds are not touching each other, one is connected to the clamp at the top and one to the clamp at the bottom of the metal box.
couple of questions
1. do i need to use any special gauge or type of wire? im pretty sure i have some 12-2 laying around if that will work.
2 can i leave the insulation on it?
3. do i need to connect the wire i add to both ground wires or just fasten it in with one since both are connected to the box?