Earthing Light switches?

[IT Yorks]

Looking for a little help, a family member who is selling a house has been told that most of the light switches have no earth. These are metal back boxes, plastic face plates and of course metal screws. The switches are wired using singles, but not in conduit, so running an earth cable would involve digging into the (newly decorated) walls.
Could the metal back boxes be replaced with plastic to avoid this?
If not, then is the work notifiable (Part P - confusing)?

Thanks.

PS. Have spent a few hours searching through your site before posting, but do apologize if I missed the answer.

 

[jj4091]

have they had the rest of the electrics checked? sounds like a possible complete re-wire.

 

[Adam_151]

I hope these singles are double insulated singles, anyway I expect its about time for a lighting re-wire... having no earth on lights dates the circuit to before about the mid '60s.... (you really should have considered this before decorating )

Anyway, the answer you are looking for, in the short term to make the circuit compliant in this respect you can buy nylon m3.5 switch screws

 

[IT Yorks]

Thanks for replies.
Like I said it's not my house, just doing 'the leg work'. Gonna look into the nylon screw option.
(BTW cables are double insulated and in good condition from what I saw )

 

[JohnD]

The buyer will very likely want to redecorate to his own taste, and may well want to have the house rewired.

I doubt money spent on the old lighting circuit will be repaid in an increased sale price.