I’ve been a pro-sound engineer for 40+ years and a musician for 50+ years. During that time, I’ve witnessed hundreds of shock events on performance stages, recording studios, and even factory floors.

The concept of an outlet tester is pretty simple: plug the gadget into a suspect wall receptacle, and an array of LEDs light up in various patterns to alert the user to any wiring faults. They’re ...

Q: How do you find out if an outlet isn’t working? — Jane in Providence, R.I. A: A voltage tester is your best friend in this situation, allowing you to test a receptacle for electric current without ...