From wiring in the home to your MP3 player, electrical wiring is everywhere in our daily lives and is normally completely safe. Yet problems can occur if wiring gets wet, as this can corrode wires or, even worse, send an electrical current into your body if you touch it.
If you've knocked over a cup of tea and spilt it over your mobile phone charger, chances are that everything will be fine. The wire actually contains three smaller wires: a copper ground, a live wire and a neutral wire. As long as these are not exposed, then you can unplug the appliance and let the wire dry naturally, as the outer layer is just plastic. As a precaution, you can use a Portable Appliance Tester to check that the appliance is still working properly. These can be bought online or in hardware stores. If the socket or plug itself has got wet, then this will require further attention, as with exposed wiring.
Where the ground, live and neutral wires are exposed, this presents more of a problem. In most homes, ROMEX® wire is used for electricity, where the copper ground wire is wrapped in paper and then, in turn, wrapped in the live and neutral wires. If this wiring is exposed either through a break in the plastic coating or even at the socket, the moisture can be soaked up by the paper, creating rust. Rust is as much a problem on small copper wiring as on any larger metal surface. Water also can start a fire. The presence of moisture can rapidly increase the current in the circuit, which in most modern appliances will cause a short circuit as the fuse is blown. However, if a fuse is not present, then the wire will heat up and a fire could start. Water can also conduct electricity to your body if you touch an exposed wire, as the ground wire is designed to return electricity to the ground, even if that has to pass through your body to do so.
If you're the unlucky victim of a flood or burst pipe, the wiring situation is inevitably going to be far worse than an everyday spill. In this case, it's best to turn off the electricity immediately and call for a properly qualified electrician. Water will get everywhere in very little time and even the smallest amount can corrode the wire and make it dangerous to touch.
With major damage, qualified electricians need to survey the area before you can even consider returning to the area. If you suspect there is a chance of a flood and of that affecting any wiring, you should immediately turn cut off the electricity supply at the fuse box and not turn it back on until it has been checked by a professional. Day to day, even smaller repairs should be carried out by professionals thanks to the danger of electricity. If moisture has entered a wire, they may be able just to cut out the affected area, but major damage may require a completely new set of wiring,.