I have an outside halogen light with a PIR sensor i want to move the light as it dosn`t work and replace it with a double light with PIR sensor but there are two wires going in to the light, my neighbour has the exact same light but with only one wire going in, can somebody please exsplain this to me why in simple terms, Thanks in advance if you can help.

George Aylesbury., October 2011

Presumably you mean 2 'cables' and not 2 'wires' - a light wouldn't work with 1 'wire' because the electricity would have nowhere to go.

Either one cable is a live supply and the other goes to the switch, or one cable goes on to the next light.

Adam, January 2012