If you have a cavity wall, and it hasn't been filled with foam, then drill holes in the appropriate places and run the wires through the cavity. If you're really sneaky, you can make the "other end" next to a power socket.
Fishing for wire through a hole in a cavity wall is right up there with watching paint dry as a thrilling exercise. When you get it through, keep a spare string there for the next wire you want to pull through.
It beats chasing out the plaster, installing conduit, and making good.