Corrosive Metal Conduit
The picture above was taken in an attic and there were no
water leaks to be found. This damage was caused from two different
metals creating electrolysis. Now you're probably wondering what
electrolysis is. To put it in layman's terms and not to get too
scientific, it's when two different metals create an electrical current,
like a battery and over time this will cause one or both metals to
As you can see in the picture above, the corrosion to the cable is worse than the electrical junction box. If you notice the romex electrical wires that are entering the other holes in the junction box, don't have any damage to them or at the junction box.
This home repair should be made by a licensed electrician or someone who has experience working with home electrical wiring. This is a difficult home electrical repair.
Home Repair Tip: Make sure that the metals you are using are compatible with each other, for all of your home improvement projects. This would also apply to aluminum windows, gutters and roof flashing. You should use galvanized nails with galvanized metal, copper nails with copper metal and galvanized nails work pretty good on aluminum windows. Sometimes aluminum nails are soft and break easily.
Read directions or check with the manufacturer of any building products that you will be assembling, to find out what nails or screws will be compatible or recommended for their products.