We've been in our house 12 years and inherited a brick-built shed with a waterproof switch outside that operated a PIR controlled outdoor carriage lamp. A strange set-up, I know
The PIR got rainwater in it and I decided to re-wire it without the PIR. I spent a few hours on the lamp, then went to the twin and earth wire that supplied it , cut the corroded ends away and received a small shock.
I checked the switch was turned off and cut the wire again....and got a spark!
So I took the switch apart and removed the switched wire. I knew it was the switched as it also had the wire that goes to an LED.
I still got a spark when I trimmed the wire again.
I gave up and put the kettle on.
On reflection, the switch had a red supply wire and a black switched wire, but the wire at the lamp was normal twin and earth, so there must be a junction somewhere, but why the power at the lamp end? It all worked correctly before the PIR as damaged. Car wiring I understand.....house ring mains not so good...
Thanks for any guidance.......
Edited by joiner, 17 April 2016 - 07:25 AM.