OK, As the cause of this thread, I'll apologise to Daniel for being flippant in my original post. It happens a lot on discussion forums with a bunch of armchair engineers...!
The point I was hoping to make has clearly been picked up - that wiring up a mains switch is not insignificant - if you don't know what, how or why you're making connections.
The device may work fine 'now', but what about under unexpected fault conditions or crossed mains situations. Insulation clearances etc.
No one is being mean or 'personal'. We're just trying to prompt each other to 'think' in the proper circumstances. Hopefully it worked. Thanks.
--- if you're looking for invisible energy burns, try high-power RF injuries, like a TV transmitter etc...
You don't even have to touch the gear - just be in the wrong place under the wrong circumstances. Sobering.
You would really have to work hard at it to get a decent RF burn off a TV transmitter.
All the high power RF connections are made via very large Coaxial Cables.
Even climbing around on the tower won't have any discernible effect---I've done it!
Also,remember that the transmitter's real power is only a fraction of the quoted EIRP,so a "100kW" station only produces around 10kW or so if you measure it into a Test Load.
You are much more likely to get an RF burn from a high power MF Broadcast site,where the Mast is actually the antenna---the whole thing sits on a huge insulator.
MF transmitter sites are rated at the actual power the transmitter can feed into a Test Load,so a 55kW MF Broadcast station produces just that --not EIRP!.
Even so,you have to be quite close to a "hot" antenna structure (& the ground at the same time) to get a life threatening injury.
People commonly cimbed on,& worked on "hot" antennas in the past.
The reason it is not done anymore is because of concerns about the possible effects of working in strong RF fields,not because of a plethora of burns among station personnel.
OK,various artifacts around such sites can give you a nasty burn due to RF pickup,but you do have to touch them.