Any project involving electricity can be dangerous. For this reason, some areas allow only licensed electricians to repair or add to a home's wiring. Before you start, consult your local laws as well as any building codes that apply to your project. Faulty wiring can cause a fire or electrocution, so follow directions to the letter and consult a professional if you have questions.
If you're working on lighting, outlets or wiring, cut the power at the circuit breaker first. If you need to test wires while you're tracing, use caution. Handle all your tools with care, and wear gloves and eye protection if you need to cut into the wall or floor to find or fix your wires. Handle hammers and saws carefully, and keep an eye out for exposed nails, wires and other potentially dangerous items. Never reach into wall or floor spaces if you're not sure whether the wires behind them are live, and use nonconductive tools when working on wiring.
If you're going to use the method of switching the circuit breakers on and off, keep in mind that you'll be in the dark as you move from one location to another. Don't cut the power to areas where lights are necessary for safety reasons. Before flipping circuit breakers on and off, unplug appliances so they aren't damaged by the constant changes in power.
To learn more about tracing electrical wiring, visit the links on the following page.