I have recently rewired a four bedroom house for a friends parents. One the first inspection visit, I went into the attic, "Throw down the cable with the plug on it" I was asked. I passed it down, stupidly now I know. He proceeded to plug it into a socket outlet on the landing. Swiched on, and hey presto we have lights in the attic.......... After no more than 20 seconds, I shouted "Switch the socket off" I came down, unplugged it and told him never to plug that in again. "why" he asked, "We've always used that for the lights up there". I proceeded to open the plug firstly, 13 amp fuse....... secondly, other end of the flex, another plug containing 13 amp fuse. This plug was plugged into a socket screwed upside down on a roof truss. And to top it all off, this provided the power to two 100watt bulbs in the attic. But the cable running to these lights was speaker wire. It was still hot when I had removed it and showed him......"Thats all I had and its worked fine for years" he said. "I think you have just been very lucky I replied" The jobs finished now and everythings safe and up to regs. He now is the proud owner of a totally rewired house and two energy saving lights in the attic running of the upstairs lighting circuit and operated by a pull cord switch which you operate when the hatch is open. The earth wire attached to the TNS supply was only 4mm and there was no other earthing accept for the cpcs in the cable. I have found that many people think/assume that if the electric works and the telly switches on ok, everythings ok. Especially the older generation.