Can I split off a light switch to add a 13 amp socket?

Obviously I won’t be doing it myself, I’m just curious if it’s possible before I start ringing around for quotes.

I have a light switch in my downstairs hallway. Want to add a 13 amp socket (preferably double but single is fine) 3ft directly below it. Nearest socket is on the adjacent wall. Would like to avoid the simple solution of just running an extension as it’ll look untidy.

Could a sparky split off the light switch cabling to add a 13 amp socket?