Turning off a towel rail
There is probably a switch just outside the bathroom. 

If this is rented accommodation your friend would have to ask the landlord's permission to get any changes made.

There won't be an "actual plug" underneath the cover. That's just a fixed-wiring outlet called a fused connection unit (FCU). 

You might be able to add a pull-switch (cord to ceiling-mounted switch). This would probably be safest.



You could probably replace the FCU with a switched version (SFCU) if the outlet is outside the zones specified in the regs. It has to be at least a specified distance from the bath, sink etc.







You may be able to get IP44 rated SFCUs.