Letter-box style bristle-hole single gang socket

["Paul Robinson" <ukcueman@xxxxxxxxxxx>]

Don't know if such a thing exists, but I'd like a single gang socket that's
just got a
hole in it for pushing cables directly through rather than terminating on
the socket. To
make it tidy, it would ideally use the letter-box trick of some sort of
bristles that hide
the hole, while still allowing things to pass through.

Anyone seen such a thing or have ideas on how to make one?

Thanks,
Paul