In article ,
somebody writes:

Huh? I've had a number of rooms skimmed now, no cardboard and no
difficulty finding the back boxes... I really can't see how on earth
they'd get 'lost'?

Maybe your good intentions (cardboard in the boxes) suggest to the
plasterer that you want the holes covered? I dunno?

I am the plasterer in this case. I prefer to use the cardboard
as you then get a back box with no plaster or PVA in it.

For me, the last thing of the day (if & when the plasterer's labourer
forgets) is to go round the edges of the sockets & switches with a
stanley knife, but it literally is no more than a "clean up the edge".

Likewise. Be careful not to nick the cable with the blade.

--
Andrew Gabriel