Well now, let's not disparage the insides of a bullshit machine; I got a discounted "ghost detector" on eBay, the insides are an antenna and a low frequency electric field detector... if you forget about the outside "ghosts" part, it makes for a decent live wire detector (oh noes, there's ghosts in my walls! /s).
I used it to found out which way to plug an unpolarized box fan plug into an unpolarized socket, so it doesn't keep the motor hooked to live all the time.
If we could see the insides of the "e-meter", who knows what practical uses could be found for it!