Perhaps you want to do some electrical work around the house like changing out a broken light switch. A non-contact voltage tester can help you determine when the power is shut off.
The device only costs around $15. It alerts you to the danger of electricity still running through the wires by beeping and changing color.
"It's worth every penny," says Jeff Lee from Mechanical Heating and Cooling. "It gives you peace of mind so that you can go ahead and do your projects without getting harmed."
Click on the video player above to watch this edition of "Fox 2 How To" for a demonstration on how to use this handy tool.