Next time you have your NCV handy grab hold of the insulated portion of a hot wire or hot and neutral extension cord(works either way) with one hand and test your nearest partner with your NCV in the other hand. Lol wow hes hot. Its a neat trick any insight on the subject?
I have been told its due to a capacitive factor of the insulation between the wire and your skin. I have not grabbed a bare hot wire to compare to. I dont pretend to understand this one. I assumed its similar to the shock risk of an ungrounded system?