The previous owners of my house had a nail in the wall just above the light switch. This gave me a slight shock and it was removed. I had the whole house safety tested and was given a certificate. I have just replaced the old plastic light switch for a stainless steel one and connected the earth to it for safety. When I tested it with a continuity tester the earth did'nt seem to work. I checked where the nail had been and opened the conduit and the earth wire has been completely severed and the two red switch wires are slightly discoloured at this point.
What is the best way to repair this? Can I connect it back together with a crimp or connecting block or will i have to replace the whole wire from the switch to the light?