I've had very similar experiences to what you call "Incubus." (Which I always was under the impression was a type of demon ... not that I am religous, I am agnostic)
My stories get wierder and wierder, the suddenly stop.
When I was 13 I got involved with some hippie sort of people, I guess as a rebellion agains my folks. (This was the 80's so they were throwbacks to an earlier age)
They practiced meditation, yoga, astral projection and even ... trying to unlock mental powers like ESP.
So I tried to learn these things, took tests like being blindfolded and sorting through 100 colored stones to pick out the two that I had chosen as "my power stones." Not only did I do it once, but I did it 3 times in a row, picking out my stones exactly. (They were all the same shape.)
I tried astral projection, but a lot of wierd things happened so I won't go into that...
A few months after I decided things were too wierd hanging out with the hippies, (well they were wierd too and they didn't wash very often ... too much Crosby Stills and Nash too ) something very wierd happened.
It was around 12:30 on Friday night. I woke up with the sound of rushing waves in my ears. I couldn't move a muscle in my body and seemed to still be half asleep. The door to my room was now open, where it was Shut when I had gone to bed and there was a dark coalescing shape there, just pulsating with darkness. Growing and diminishing silighty with each rushing of the waves. I was terriffied, but I struggled to move, to break free of the dead weight that held me in place. It was to no avail.
It seemed like an eternity but the shape in the door started to get bigger as the sound of the waves increased in my ears, and diminish slightly less until I blacked out.
The door was still open.
The next morning I remembered it clearly. I didn't sleep at all the next night. The night after that I slept with the light on.
One month later on Friday night at 12:30 it happened again. Much the same as before but this time I seemed to be able to undo a bit of the paralasys, and move my hand a little. It didn't make any difference, I still ended up passing out.
Fast forward another month, Friday night 12:30. I made up my mind that I was going to stay awake this night. I was sitting in bed reading at 12:30. Nothing happened. I did it! 12:40, all right! 1:00, excellent!
1:05, I put the book down ... and the light went out by itself. I couldn't move again. I was in a half-stupor like before but somehow aware that I was. I fought like mad and managed to move a little bit but still the same thing happened.
The next month I decided to use some of the stuff the hippies taught me. Friday 12:30 I was in bed, door closed, ready. Suddenly I felt the paralasys, heard the waves saw the figure in the door in a half-stupor. (I never did see the door open it was closed, then open)
I began to concentrate on white light eminating from me, surrounding me, as I did this the sound of waves got quieter, I felt more aware and more in control. I started to concentrate on porjecting this white light out, surrounding my bed, and I began to be able to move my arms and legs. I was awake. I concentrated on moving the light out and the figure started to move back from the light, until I had filled the room with this (mental, imaginary, it was still dark in there but I saw this light) white light. It was gone, but it didn't shut the door behind it.
It never happened again after that. (BTW, concentrating on white light is the same as imagining white light)
Finally the last happened when I was in HS.
I had a friend who's house I would go to after school. She and her brother would sometimes stay up late and play with an Ouija board. I don't know what they did, but whatever it was strange things happened in that house.
She used to collect those cards that played songs when you opened them, she had about 50. Once when I was there she showed them to me, and then we just left them stacked on her dresser and left her room, closing the door behind us. We went about 2 steps down the hall when we heard this incredible musical racket from her room. We turned around and opened the door ... all the cards were spread out all over the room ... all opened and playing. Some were on the bed, some on the dresser, some on her desk, some on the floor, but every one of them was open and they were all facing the door!
Another incedent at her house, it was getting late in the day and it was getting to be time for me to be going home. I said "I wish I had more time." Suddenly the clock on the wall jumped in place, so we looked at it ... it started going backwards! We watched it rooted in place with terror until it stopped at the exact time I showed up. (No, time did not go backwards, just the clock!)
Things were always ending up in places where they weren't put that house, but my favorite story is saved for last:
Her brother and his friend were playing foosball one day. He had put a glass of milk on the windowsill ... it was a deep windowsill, probably 2 feet deep. He had put it about halfway in. It also slanted toward the window, not toward the inside of the house. He and his friend were joking around about feet. His friend said "well your feet smell anyway."
At that moment the glass of milk slid about 9 inches up the sill and tipped over ... and spilled the contents onto her brothers feet.
A ghost with a sense of humor.
Nothing wierd has happened since then.