Where does the &**^& wire go

J is away this weekend seeing our friend in Brum who has just come out of hospital.

Came home to sand down the woodwork ready for the paint later in the weekend. Managed to get most of it done. We also plan on putting the TV on the wall. As I can't stand to have wires on show the plan was to tap into the ring main and put another socket up next to the TV and also move the TV aerial socket up high as well.
The power socket isn't too bad but I couldn't find where the ring main goes, think it must go under the floor. The main problem is finding where the TV aerial goes.
Feeling inside the wall it looks like they have put it under the floor. Still a bigger assault tomorrow when its light might reveal the answer.