It may depend when your house was originally wired.
If it was not too long ago, there may already be conduits plastered into the walls and the electrician will be able to use those to pull the new wiring through.
But if not, he will have to chase out the brickwork to install the new conduits for the wiring, then replaster over them to conceal them and then pull the wiring through the new conduits. This can be a messy job so be prepared!
Whatever you do, try to get someone who has been recommended by someone you know/trust and, if possible, get a couple of estimates.