small electrical charge on truck camper frame

I remember about 20 years ago , I put a lick it type dog water deal on a faucet on my front deck , my GSD wouldn't use it even though she had used it elsewhere all her life. I finally grabbed hold of it and made water come out and got a weak elec charge , seams there was a nail on the deck apron going through a romex slightly and then touching the copper water pipe
Luck I caught it before the shock therapy ad her off the lickit for good