Thanks for the reply Benjamin. It's not really what I'm after though.

My problem is that I have a problem with the wiring between a ceiling
lamp and the existing light switch on the wall on the opposite side of
the room.

The ceiling lamp has power but there is no continuity to the switch.

I want to install a wireless switch on the wall in the same place as
the existing switch and install a receiver at the lamp to switch the
lamp, rather than chase out and redecorate.

sorry if I was not clear before.

Thanks,
Andrew