I share the sentiment of being grateful that I stumbled upon this topic. Like most of us here, I was told by my partner that I vibrate when I'm sleeping. So intensely that it wakes her up. Supposedly, It happens as soon as I "hit the pillow", but I'm not aware that I'm doing it. However, the few times that I've been rousted out of a sound sleep by an elbow in the ribs, I have noticed the bed vibrating.
Prior to this happening in the "marital bed", I've never had anyone else say that I do this. When I was in my late teens, I was experiencing a lot of trauma: death of a parent, sexual abuse and was, at one time awakened by my bed vibrating violently. I have no doubt that it was "me". You know, possible TK or internalized anger manifesting itself then exposing itself via the shaking. I'm speculating, of course.
I am a firm believer of chakras, third eyes and the like and I do belong to various paranormal research groups in my area so, I've been told that I'm just a "beacon" of sorts and what I'm experiencing is a "psychic orgasm". Nonetheless, I have had all my systems checked and all is okay. Maybe we're just unique?

One other thing, it never happens when I'm sleeping on the couch, but I do take "my gift" along with us on vacations.

It's comforting to know that I'm not the only one. This is relatively new to me. I am F, 47 - about five months ago, out of the blue, I started having extreme insomnia problems. I went two weeks with almost no sleep. I didn't want a pharmaceutical solution, if possible, and I began trying all sorts of herbal/natural supplements. Occasionally, I tried over-the-counter sleep pills, and THEY didn't work. I've become convinced that this, for me is related to perimenopause, although I haven't missed a period, had night sweats or hot flashes. I've found an routine that enables me to sleep somewhat now, and I use low doses of the supplements 5-HTP (an amino acid that produces seratonin, and usually calms the central nervous system - it certainly calms the brain,) and melatonin - although I still wake up after 4 or five hours or so. Lately, when I do wake up (I, too am a side sleeper) I've had the "buzzing." It started with my feet and legs, but now it's my whole body, a very fast low vibration. It's too strong and distracting to let me go back to sleep, but if I get up and use the bathroom, it's stopped when I get back to bed. I believe my insomnia is hormone related, but I've been checking kidney function, too (perhaps a little low.) In my early twenties, I was obsessed with having an out-of-body experience, but I did not (consciously,) and I use to meditate and get into some very deep mediative states, but that was many years ago, when I was a vegetarian. I was buzzing away last night - there is a new moon tomorrow.

wow! i thought i was weird with my body vibrating until i stumble at this site, i read all the comments and i got to say.. i love my body vibrating the way it does.. and it has been vibrating for years, about 15-20years, most of my life and it happens most of the time when i am very tire, or sick, or goin trough in life... and when it does i could swear i could feel my body getting better..phisicaly,mentally and may i say it.. spiritually.. i love it! not very into comicbooks but i could say our body goes into ultra-healling prosses when we sleep and there fore our viration, anywhoo i love it that i have something in comon with my cat! lol thanks 2 all for all the comments.

I have been vibrating almost all my life that i can remember
it seems to happen when my mind is at high speed (constant thinking) I do have sleep apnea, I can control all my dreams I know when i am dreaming which allows me to control the dreams.

I always vibrate when my mind is on high, so i tried experimenting with cocaine and Meth the meth i stopped when i found out what was in it, but, with both substance
put my mind on high and the vibrations would happen with out sleeping just lying in the bed and higher vibrations.