I don't think the criminal system should deal with supernatural threats to people. Witch hunts? I want the criminal system to be completely neutral on the question of even the very existence of supernatural forces. So, there is no prosecutable crime in invoking supernatural forces that are not known to exist.
The current law isn't neutral on supernatural forces. Not only does it assume that supernatural forces do not exist, it assumes that no reasonable person would treat them as if they do exist.
Out of curiosity, though: if you think the supernatural exists and can be demonstrated to exist, why
wouldn't you want the law to recognize this?
I mean, if the supernatural is real, this amounts to letting criminals get away with their crimes.
If we really could, say, get the spirit a murder victim to testify in the trial of their own murderer, this could revolutionize the justice system for the better... if it actually worked.
Now, I don't think we should try to do this because I
don't think it could actually work. I think that any "medium" purporting to channel a dead person is either a charlatan or mentally ill, and I wouldn't want such a person anywhere near a witness stand.
I have no idea why
you wouldn't be behind the idea, though.