shock from bathroom light switch

[WillyWarbucks]

Hi there, I recently moved into a house and me and my partner have both sporadically felt a slight buzzy/electric-shocky feeling when switching on a light in the bathroom.

I think it happens when you have 1 finger on the screw of the casing and flick the switch at the same time.

What might be causing this? I've attached a photo of the switch's innards. The bathroom has 2 lights.

 

[bernardgreen]

No earth to the metal mounting bracket. Capacitive coupling from live wires to the braket will bring the metal to live potential. Shock from the screw is ( so far ) only a tingle as the current is limited to a very low current as it is only capacitive coupling.

Main danger is the insulation on a live wire becomes damaged and allows the live conductor to touch the metal bracket This would create the risk of serious shock from the screws.

Replace the metal screws with nylon screws.

Consider re-wire to bring an effective earth to the switch or replace the switc with a ceiling switch with pull cord.

 

[WillyWarbucks]

thanks for the reply. nylon screws. I'll get on that straight away. We're really not too happy about the switch being inside a steamy bathroom, will look at having it moved outside or to a pull cord.