Hi,I'm looking to change the outlets and the switch and light fixture in a bedroom of a home built in 1948. The outlets are original to the home I think. Will I have to fish ground wire throught to the panel box for my new receptacles? Or just install new 2 slot outlets?Why the different looking wires?Is the older wire copper with a silver colored coating to indicate being neutral or is this an old aluminum wire? The hot wire is red plastic coated and looks modern to me.
In '48 your house won't have a ground wire as you found out. If it is wired with BX cable ( metal clad) you can see in the basement or crawl space, the ground is actually taken to the outlet by the metallic casing. Then all you would have to do is get a bag of ground wires with screws already crimped on them at Home Depot called Greenies. You screw them into one of the holes inside the box and attach the other end to the ground screw on the switch or outlet. The red casing you are describing actually sounds like red electrical tape wrapped around deteriorating wire in the box as the other wire looks raggy. The wire you see that looks aluminum MAY be aluminum someone added in the '70's when al wire was used, but BOTH would be replaced and there would have been a ground wire. I don't know why it looks silver, but I have seen old wiring like that and it is usually copper. If you see the BX cable you are good adding the ground wire, if it is a silvery looking cloth casing, then install new NON-grounded receptacles.
it is normal for a house built in the late 40's --- it was thought, at that time, that the aluminum wiring was cost effective and the most up to date === it would be wise to pull new wire and that would be 12 gauge with a ground [[ two wires, a black
you've got some good answers so far. if the wire turns out to be aluminum then proceed with caution because aluminum wire in small sizes turned out to be a terrible idea. it will need a special receptacle. if the wire is bx wire as described in your first comment don't bother with those greenies he mentioned because simply screwing your device into the metal box will bond the ground together. it uses the 6/32 screws provided as an excellent grounding means. you may want to consider using GFCI receptacles as well. I've never seen a new hot wire and old neutral wire like you describe and I've worked on a lot of older houses. before you get into trying to rewire your house realize that this is a very time consuming and aggravating project that will require two people who really should have experience doing this. if you do it then invest in a long (like 4 foot) drill bit and some glow sticks.
