When the electricity in part or all of your home doesn't work, the outage may be caused by any of several problems. Your first step is to determine the extent of the outage.

If you see sparks or evidence of electrical shorting, shut off the disconnect device that serves that portion of your home and call an electrician. Do not do your own electrical repair unless you are accomplished at and knowledgeable about electrical work.

Follow all safety precautions: Never work on live electrical wires; always shut off the circuit first. Do not stand in water or on a damp floor, even when working on low-voltage wiring such as telephone wires.

• How to Test an Electrical Circuit
• How to Trace a Short Circuit or Overload
• How to Turn Off the Power to Your House
• What to Do When the Power Goes Out
• What to Do When There's Only Partial Electricity in Your House