No, this is totally different from lucid dreaming. Lucid dreaming, your still dreaming, you just realise your dreaming. Sleep paralysis is when your body is paralysed(natural part of rem sleep), but your mind wakes up,
It's scary as you are awake, but unable to move. Can't scream can't do anything.
After the first time or two you realise what it is and it's not that scary. Apart from last night where I couldn't breath as head down on the pillow, bad timing.
You can also experience hallucinations. Which can very from benign to terrifying.
Had massive flaming Satan in the room, alien doctors injecting my stomach, room full of snakes amongst others.
The most common feeling with sleep paralysis is just a weight on your chest and a feeling of an evil presence. Making it feel like you're being pinned down by a witch, evil spirit etc.
You can't scream. Which is one of many reasons it's scary the first few times, until you are able to remember what is happening.
Well thoughts are very powerful, so those with negative ones will be forming such hallucinations that you mention. Fear is very powerful and runs most people's lives but they don't realise it. Maybe the whole paralysis thing is linked with it in some way I don't know.
Anyway going a bit off-topic here but more and more people are reporting OBE experiences which is in itself a good sign of the increasing levels of spirituality among us. I think it's going to be a big topic in the future with lots more research being carried out and facts coming to light. Also more people experimenting themselves of course.

