Read somewhere that if I want to be super safe I should not only cut the breaker, but also use a voltage detector to be 100% sure there really is no current.

Looking on ebay they are real cheap: enter image description here enter image description here

It says the voltage sensitivity is 90~1000V AC. Can I use this to test light switch fixtures? Is the voltage sensitivity right for this purpose? They are so cheap I want to be sure the voltage sensitivity range they are rated for is adequate.

  • Voting to close because where you buy your hardware is completely irrelevant to anyone else on this site. The scope of this site isn't to address ecommerce fraud/safety.
    – Steven
    Commented Apr 8, 2015 at 13:53
  • I think the question can be re-stated to ask how effective these devices are, and if a voltage detector can actually be reliably used to detect the lack of current.
    – Hightower
    Commented Apr 8, 2015 at 13:58
  • I reworded the question. Please let me know if its ok now.
    – red888
    Commented Apr 8, 2015 at 14:23

1 Answer 1


A Non Contact Voltage Detector doesn't replace the need for a Voltmeter but it is an item I keep in my pocket as a quick verification of AC Power. If I cut the power, I'll do a quick test before I go into a wall box to make sure it is cut. If it indicates power when I don't expect it, I will use the volt meter at time to see what it is.

I do get a number of false reads with the device, so if your life depends on it use a volt meter instead. Also this is a safety tool, real cheap doesn't really sit well with me. I'll rather spend $15 dollars at a hardware store for this from a known brand than get an unknown brand/quality.

  • Personally, I just stick with a voltmeter as more reliable and more generally useful. Since it "doesn't replace the need for a voltmeter" I see no point in having both...
    – Ecnerwal
    Commented Apr 8, 2015 at 21:15
  • 1
    The non-contact type saves a lot of time. I've had false positives, but NEVER false negatives. Sometimes pulling a bundle of poorly terminated (wire-nutted) wire out of a junction box to probe it with your voltmeter is more scary than waving a wand around to get an idea of whether it's hot or not.
    – William S.
    Commented Apr 12, 2015 at 2:27

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