Running cables for doorbell

Hi all,

My house doesn’t have a wired doorbell. I’ve been considering getting a transformer installed to provide a low voltage power source for a wired Ring or similar doorbell, as I’m having mixed luck with the battery powered variants. There is a ring main socket in our hallway, on the other side to the front door, so I assume I could have a sparky fit a transformer and spur off the socket.

I’ve seen lots of talk about how you aren’t supposed to run cables in a cavity wall. If this is the case, how am I supposed to get a cable through the plasterboard, out of the inner cavity and to the other side of the outer cavity? It would be going directly through the wall in a straight line.

Any help or clarity greatly appreciated.