One thing that is widely reported from meth users is they hallucinate and see "shadow people". From my own demonic experience, in my opinion these "shadow people" are not hallucinations. They are demons, unclean spirits, disembodies spirits.
When I was a teenager, and not on drugs or into the occult, I woke up to see the gray shadow outline of a figure standing by my bed - just like the shadow of a person, minus the person.
I instinctively pulled the cover over my head and asked God to make it go away.
That was the only time this happened, and I didn’t know until decades after that, that people all over the earth see such shadow figures.