Most of my house has been professionally rewired in the past 18 months, the only exception being lighting in two ground floor rooms. Some of the old wire has been disconnected but left in place (for example where a light switch is no longer required). Not a problem in itself, but the exposed wires in two locations (ground floor and first floor) are coated in a dark green slime - wet to the touch. On the ground floor I have a wire which was previously connected to a 2-way switch. It is PVC coated, twisted strands, the colours are Red, Blue, White (maybe yellow) Brown and an unsheathed wire. Has anyone seen this before or do I need an excorcist?! 
