They'll typically use something like this:
This flexible bit is about 4' long. You cut the hole where you want the outlet, then insert that flexible bit to drill through the floor or ceiling, inside the wall. The cable is routed through the basement or attic.
If basement or attic are inaccessible, you can drill horizontally, three studs at a time. You'll have holes every 4'. If you are creative, you can install new outlet boxes in those holes, and not have to do any drywall work.