you could argue that when you become "one flesh" with your wife that its applicable here tooI never really thought about it that way, but it makes sense to me. Witchcraft and the like is a person making a pact to be under the power of whatever they are trying to communicate with, so essentially they reject G-d and being under G-d's power.
So they are locked to wherever the spirit they linked themselves is.
remember in that other thread when I broke down how Laban tricked Jacob?
