Lighting Circuit Showing 12v When Switched Off

Hi,
When I moved into my house the back room had cable protruding from the wall with connector blocks and taped up, where some wall lights where. I don't want any wall lights so wants to lose the cables, etc and patch up before decorating. Trouble is when I checked if they where still live, they are showing 12v on my tester and the full 240v when I use the switch.

Any ideas why it is showing 12v?

Thanks in advance.

Stu

Inductance and/or capacitive linking specially if part of a two way system.

Its possible that the 12V is due to the mutual inductance from adjacent circuits or a dodgy multimeter