Unlike many of my friends in high school - and many in the 'truth' - I've never had a hallucination. Maybe I need to say
that I've never knowingly had one, because there's always the possibility that I had a really good one, that I mistook for reality.
After reading some books on consciousness, I note that there are some simple tests for distinguishing reality from hallucinations,
all derived from computer analogies. They concern 'bandwidth' and 'memory' issues.
It might take a lot of your brain to 'create' a simple ghost. It would take even more to make the ghost three dimensional.
Can you look around it? View it from different angles?
How about smell? Decay? Ozone? Perfume?
Does it make a noise? Is it directional?
Can you touch it and feel it? Does it have color or is it just monochrome?
Does it interact with other real objects? Leave footprints? Spoor? Blood stains?
Basically, the more of the five senses that get used in verifying an event, the more likely it is that you've encountered
something real. It takes more and more of your consciousness to fake something and get all the details correct.
I've had friends who had private hallucinations - and viewed them as annoyances they had to put up with,
usually after a mispent youth involving illegal substances.
I find ghosts interesting because they often look more a loop in a computer than a wished for hallucination
- repeating simple tasks over and over, etc. - rather than discussing the afterlife with worried relatives.
Anyhow, I've never seen a flying saucer, a ghost, a lake monster or ball lightning. I've never had a NDE or OBE either
but I'm prepared with my own questions if I do! So, does your saucer come with toilet facilities? Why not?