Electrical wiring?

This is an international group - you need to specify your location or you will get variants on the rules in the US.

Answering for the UK, as it looks like you come from there...

Sheathed cable (such as twin+earth) can be directly buried in walls according to following rules:

At a depth less than 50mm behind the surface of the wall, you can do a horizontal or vertical run from any visible wiring accessory, or within 150mm of a corner or below the ceiling (but not the floor). Oval plastic conduit or capping is often used, but is not a regulatory requirement.

A wire can be buried anywhere in a wall if protected by an earthed metal sheath, eathed armour, eathed metal conduit or equivalent, or buried deeper than 50mm behind the wall surface.

Singles without a sheath (e.g. separate live, neutral and earth) must be in conduit.

Sorry hadn't realised, I'm in the uk.

Alan

Thanks.

Alan