metal light switch case registering live - worried!

[jamiller]

I have swapped a plastic single light switch for a chrome one. I connected the red, black and earth (box and switch). When I put a screwdriver tester on the chrome, it is registering as live (lights up inside handle). The case is not live to touch and the light wiorks fine. Can this be explained. Thanks

 

[Dippy]

You need to check this out with something better than a screwdriver tester. You probably have a 'floating' cpc (aka earth).

 

[jamiller]

can you explain please - is it dangerous

 

[securespark]

If your cpc (earth) is not connected to earth at the other end, then yes. Your metal switch could, under fault conditions, become live to touch. B
This is because there will be no connection to earth to take fault current away.

 

[Taylortwocities]

SS is very right.

I just wanted to understand your logic here.
You used a neon screwdriver to test the switch plate and the indictor lit up.
Suspecting that it could be live you thought the next best step would be to test it out by touching it with your finger??