treehugger - You're right, I don't know you. Sorry if my words were a bit strong. I don't disrespect you.
Experience and study has shown me that there are etheric beings which seek energy. There are generally negative, and generally positive ones. The positive ones do not seek it from other beings, as they have a connection with the Godforce and can cultivate this & themselves on their own.
The negative ones do not, or possibly choose not to have - this connection. So when they see one who has a soul / has Godforce energy... and who is not protecting themselves (and not being protected by other positive etheric entities), they think... 'lunch'!! [there is a NR thread that talks about this, just can't find it!] Not protecting oneself could mean that there is a crack(s) in one's etheric field. Just means that that person's etheric field is not sealing them.
Now here's the interesting part... the cracks can have many different causes as I'm learning. The largest cause is perhaps that one is not doing things that one should be doing. IE - not acting anywhere near how their Soul/conscience wants. It could also come by 'absence of doing'... that is, not doing positive things that one should be doing. It can also come by having a lot of exposure to harmful radiations. Things like ELF/ULF radiation from cellphone towers, cellphones (yes... why do you think this technology is so popular), even computers, many many more electromagnetic causes. Also by pollutants in the air, water. Think of it this way: things that cause cracks in one's etheric field / protection generally fall in two categories: 1) things that are consumed by your body or mind, 2) actions which are performed or not performed. (1) generally leads to (2) - generally.
I have had a similar experience to nostrum. It was not a pleasant experience, and the effects that followed were not positive either. You can read about it in this post: http://forum.noblerealms.org/viewtopic.php?id=2842.
Ahurani, incubi and sucubi do exist. I believe we would actually be astonished by the stuff that's around us etherically!! - both positive and negative. I think most of us we would be shocked to see in actuality the (internal) building and (external) transference of Godforce/lifeforce/energy - how it actually works.
"The unknown does not incite fear, but dependence on the known does." - J. Krishnamurti