I've just been thinking about this for some reason and I realised I don't actually know... when you touch a live wire and you get electrocuted, is it the current or the voltage that gives you the zap? What causes the skin to burn when you touch it? I've seen electrical boxes that say 3,000 volts, can a person be killed or get serious harm from something with say 5 volts for example? Is there something I can plug into my electricity at home and set the amount of live electricity the comes out? I'm basically looking for something with a dial that allows me to control the voltage of electricity. Something like this http://www.dealschic.com/images/l/2992/1.jpg [Broken] but where I can set the voltage output myself.