The Klein dual ncv works well enough.
Green light- no beeps= no voltage
Red light- slow beeps= low voltage
Red light- fast beeps= high voltage
I have noticed that if I wave it around it will beep slowly. So I just make sure I get right next to the wire/circuit I want to check and hold for a second. Then double check. If I'm feeling unlucky I check with a meter!
"I've got my Gas Mechanics license"
"Yea, well my 16yr old daughter has her drivers license, doesn't mean she knows how to drive"