While I've never had what I think could be called an old hag experience, I often have strange half-dreams while I'm falling asleep or waking up. Mostly they include sleep paralysis. Most of these experiences are auditory and not very remarkable, such as „hearing“ someone rummaging downstairs (when there's no one there) or mistaking the ring-tone of my alarm clock for a school bell or something like that.
I remember one such experience where there was something visual involved though. I was in hospital to have my adenoids removed and luckily I had a room to myself. On the morning of the surgery I „woke up“ (or so I thought) looking directly at a corner of the room above the door. There, something like a shadow or a cloud was hovering and slowly moving. What amazed me most is that, before even realizing what I was doing, I was sitting upright in bed and calling „Go away. Leave me alone,“ as if I was convinced that this was some kind of living being that could understand me. There was no trace of sleep paralysis. I remember feeling neither surprised nor really scared, just a little concerned because of what the shadow might be up to. I guess that is when I woke up. The shadow was gone but I was sitting in bed, and I had obviously uttered these words aloud. This was only twoyears ago, during a time I was thinking about reincarnation and things like the soul and spirit a lot, so maybe the dream (if you could call it that) was influenced by that.
Another incident which involved the sense of touch happened only a few months ago. Again I was waking up and distinctly could feel my cat under my left hand. The fur, the purring, all absolutely crisp and clear. Most of my body was still paralysed but I managed to move my fingers, and it felt just like the cat. Then, the thought crossed my mind that Lucky wasn't allowed in here. The door was closed and there was no way he could be inside the room. The same second the furry „thing“ under my hand changed into something that felt a lot more scarier than my lazy housecat, more like a wriggling furry snake (even the purring started to sound terribly „wrong“). Before it could get too scary I woke up and there was nothing but the bed under my hand. Strange, but also not inexplicable I guess. Btw. the cat was all right and he's still with us.
The third and (initially) scariest experience happened when I was travelling along the Rhine river and spent a night in an old rustic inn. I had gone to bed around ten o'clock, when shortly thereafter I heard sounds outside like metal grinding on stone. I thought maybe something was spilled and now they are cleaning it up using a metal bucket that gets shifted around. The sound continued for at least two hours, with long pauses in between. I don't remember falling asleep, but I must have, because suddenly the sounds seemed to come up to the room's door. And then the whispers began. I could distinctly hear a man's voice whispering in what sounded like an eastern european language. It sounded quite nasty and malevolent, like some incantation or chant. I tried to move but was absolutely unable to do so. Luckily, at that time (not more than three or four years ago) I had already heard about the old hag syndrome and sleep paralysis. And even though I was half asleep (I guess) I said to myself: „okay, don't panic, you can't move but that's just sleep paralysis, which must mean that you've fallen asleep without noticing. And that means that you're only dreaming, but you have to wake up somehow“. So I didn't freak out too much and with considerable effort, I did manage to lift up my left arm (while the whispering still went on) and hit myself (not too hard) on the cheek. I woke up almost immediately, just in time to hear the sounds of a train passing in the distance, the rythm of which fitted exactly the guttural sounds of the „chant“ I had heard (with words and everything). So I guess it was just my subconscius making those train sounds into something weird.
In the mornig, during breakfast, I asked about the grinding sounds I had heard before I fell asleep, but no one could tell me what that might have been. The only other guests, an elderly couple seemed to have heard them too, but they obviously thought I had been the culprit.
So, nothing really inexplicable there. But still, I wonder if that's all just my unconscious mind mixing reality with dreams or if maybe these hypnagogic states open some channel to things outside that use it to "mold" one's perception. I once chatted online with a girl who said she's had „psychic“ abilities from childhood on and that she would get into daydream-like states at work or wherever (less at night) in which she could „see the dead“ who then conveyed some message or feelings to her without speaking. I guess you could call that a hypnagogic state too. I don't know much about psychics, but maybe it's the same with all or most of them. And wether you think they are for real or not, some of them seem to have proven that somehow they do know things they actually shouldn't (I'll refer to the studies of Dr. Gary Schwartz here).