This is the advise that usually gets people killed or the house burnt to the ground... if your not sure maybe you should not give the advise... let a qualified person give the advise...
Todays standard is a 4 wire system where you will have a black, red white and green wire... the black and red will be the hots and the white is a neutral with the green being the ground. The old standard is with just the 3 wires of black, red, and green. The reason for the change is that more and more 220 products are putting things like motors that run off 110/120 so with the neutral wire in there you will get 110/120 running on the correct wiring. This will save lives and houses from being damaged or destroyed.
I am an electrician and could probably help you out on this as I have stated in previous posts... pm me if you need help.