Most of the time there are no outlets in UK bathrooms. Some times you get an outlet that can accept a special type of plug found on shavers and electric toothbrush chargers.
I think the building code allows for plugs in bathrooms if they're far enough away from the toilet/shower/bathtub, but I've never seen a house that was equipped this way.
I've never seen a bathroom with the switch inside. They're always outside.
As for your friend's hair dryer, maybe it was a hotel with a special hair dryer built into the wall, and far enough away from the rest of the fixtures, but I also might have just made up something that doesn't exist.
It drives me nuts, as I'm sure there are technologies available in the 21st century to allow the safe manipulation of household electricity and water in close contact with each other, but change comes slowly, and fear lasts a long long time.