I had some wall lights installed in a downstairs room and connected to a two gang light switch, the other gang being for the main light. SHMBO wants two more wall lights on the opposite wall but on the same switch. The wiring to the existing lights goes down the wall, I'm fairly sure that I will be able to locate the cables under the floor of the upstairs room (haven't looked yet though), but don't think I will be able to run a new cable down the wall to one of the existing fittings or the switch to pick up a supply. What am I allowed to do to pick up a supply? Can I cut the existing wire and join in a couple of new feeds somehow, if so how? I don't think a junction box is allowed if its going to be under the floor? Thanks for any help.