I know Judaism believes that angels do not have free will, and therefore cannot be evil, but that theological issue aside it is beyond any doubt that trying to connect to the spirit world in any way is idolatrous and absolutely condemned by both religions. The fact that it's punishable by death is proof of how serious it is. Do you know by any chance how common it actually was for ancient Israelites to be put to death for engaging in witchcraft or the pagan ceremonies of surrounding Canaanite scum?
In my opinion it does not matter whether or not the drug user is deliberately engaging in witchcraft. We know that psychoactive substances, especially when used repeatedly, contribute to mental illness no matter what. Schizophrenia, which involves a total disconnection from reality and oftentimes the hearing of terrifying voices which command the sufferer to hurt themselves or other people, does to me sound a lot like what was described as "demonic indwelling" in ancient times (and non-western cultures today). Regardless of whether or not it is, I think we can agree that marijuana is very bad (with the possible exception of patients who truly need a powerful painkiller).