Review on 🔌 Sperry Instruments STK001 Non-Contact Voltage Tester (VD6504) + GFCI Outlet / Receptacle Tester (GFI6302) Kit, Electrical AC Voltage Detector - Yellow & Black by Brendan Thorpe

UPDATE 21/12: I have used several non-contact voltage (NCV) testers since purchasing this tester (which I still use today). I think it's fair to update my review to say that this tester is NOT unreliable. The problem is that it's very delicate. I have another NCV tester to test/fix Christmas lights. This one isn't as delicate as this one as the wires from the Christmas lights are exposed. This Sperry tester is sensitive enough to detect magnetic fields inside a wall. Initially I thought this tester would work on a wooden door. This door ended up next to the wall switch on the garage door. While these 2 are a few inches apart, the Sperry tester was able to detect live AC wires in the wall. It's actually good and it should be. FIRST CHECK: NCV Tester It worked on a doorknob mounted on a wooden door. No electrical contacts or wiring in the wooden door. Needless to say, when I put this on a wall or an outlet, I can't trust it. I can't believe he actually found a power cord in the wall or that every outlet I plug him into actually has power. Pretty disappointing. I've used it successfully to check the off state of devices before working on them, but I can't say it's always reliable. However, a false positive result is better than a false negative result. Of course, if it's negative (de-energized), I always check with a multimeter. Because electricity is relentless and leaves no room for error.