Electric shocks from light switch - unable to figure out why..

[mirandaparkinson]

Getting a fairly mild electric shock when touching metal light plate. Suspected faulty wiring within, but no, all OK within the box. I changed switch for good measure. Problem persisted! VAC between switch earth (=plate) and radiator is 8VAC when switch is off, 11VAC when switch is on. RCDs not tripping. What's going on?!?!?

 

[TAB]

So you have a DMM?

You need to test the resistance between the earth at the light switch and the earth bar at the CU. With power turned off of course!

You should be looking at about 1 ohm resistance for a correct installation

 

[mirandaparkinson]

Many thanks for your help, I will set up the required 5m DMM lead extension and post an update when I've tested resistance.

 

[thesaint]

You may not be getting a shock from the light switch. If your clothing has accumulated a big static charge and then you touch a metal object - or indeed a plastic light switch; the current will discharge from you to the items mentioned.