I'd like to contribute this towards the original topic;
I used to have a large amount of hallucinations when I was a kid. One time, for example, I saw probably several dozen birds appear out of nowhere, then walk a few feet or so, and disappear straight under a long light-bulb of ours. (It was positioned vertically, about 2 feet long I think.)
Another time I woke up in a tent and saw in the corner of my eye a woman and her daughter dressed in pure white.
Another time I was lying in bed, and I saw a tiny, half a foot long dog, perhaps. It was the most evil and terrifying dog I have ever seen, and it wasn't even real.
These were scary things. And I probably hallucinated maybe several dozen times, but those were the ones I can remember best. I would say that it was definitely demonic in nature. My Mom told me a few months back, I think, that she had eventually prayed and repented of some thing or other that had demonic association (I don't know what, nor if it was particularly demonic, but she repented of something), and apparently that's when they stopped. I don't see things anymore and don't think I have for years. Many years.
After all, nowhere in the NT does it mention demonic possession being permanently destroyed, and even in Acts they had demon-possessed people. It might help that my Mom and my step-dad used to do yoga. My mom doesn't anymore, but my stepdad does. (He's not Christian.)
The best thing I can say is; look for anything which may be associated with the occult or with demons and get rid of it. Or repent of any involvement you've had with such things in the past? I don't know if this'll help.