I removed an old garbage disposal from a house I just moved into and was intending to replace it with a new one. The electrical coming out from under the sink in metal conduit has one white wire, one black wire, and one bare silver/steel wire. Is this bare wire the ground wire? I usually see the ground wire being a green wire, but can't think of what else this wire could be. I have a picture if needed. (The old disposal only had the white and black wires connected with no ground - it often shorted out and eventually old owners gave up and it turned to junk).