Loosen the wire clamp screws located on the sides of the receptacle there are 2 kinds of clamp screws on a receptacle one set is silver and the other is brass colored.....Put the 2 Neutral (white) wires on the side where the Silver screw clamps are and tighten each one down....put the 2 Positive (black) wires on the side where the brass screw clamps are at and tighten each one down...That leaves you with 2 wires left.......You will need an extra 4 inch long piece of ground wire so use your spool and cut a 4 inch piece of green wire or bare copper wire, this is called a pig tail....you will need a green wire cap...take the 2 ground wires and the 4 inch pig tail and hold the ends together evenly and then screw on the green wire cap nice and tight....this leaves you with a single pig tail wire coming out the green wire cap, this wire is then connected to the small ground screw on the receptacle....then gently fold wires and place everything into the outlet box nice and neat....
use 3 wire nuts and 3 jumpers, color to color and then connect the others together. Black wire to the dark screw, white color to the silver screw and the green to the ground connection. If this does not make sense to you contact a local qualified professional electrician to do the work.
I say that JimW has given you the best answer ..... sounds to me that the box that those wires are in is a connector or in-line jumper box ---- where is your multi-meter or 2-wire/glow tester to find whatz hot .... the certified electrician is going to do what JimW says ... further tests will prove it .......
