Moved into this house a few months ago. In the loft is a (clearly DIY-job) light, with a light switch next to the entrance. It was temperamental at best, often requiring the face of the switch box to be jiggled up and down before coming on. Now it's completely packed up. In a testosterone-driven moment I removed the switch box face to take a peek, and one of the wires wasn't fixed in and was sticking out.
The problem is, I've no idea which circuit this switch is on, and don't really want to touch live wires (especially while standing on a metal ladder...). I don't know anywhere near as much as I'd like to about electricity and home DIY - is there a way to find out if there's a current even reaching the wires? I could buy a multimeter, but I still wouldn't want to touch anything so couldn't really fix it up. Should I just turn off all the electricity in the house and wire it back up? I'd have thought turning off all the electrics could damage some components, or something.
Also, the switch box has been over-tightened at some point I'm guessing, there're cracks emanating from the screw-holes. Is this a risk?