Electrical engineer here. You’re mostly right–electricity does mostly flow on the outside of a conductor (a small amount does flow through the core).

But based on this picture, I don’t see an insulator on the hanger wire. Which means it’ll trip a breaker or blow a fuse as soon as you plug it in. And if it’s at your crazy uncle Ned’s house, where he casually replaces his fuses with pennies, you’ll get some visitors in a fancy truck!