About a year or two ago I tried out some lucid dreaming and followed the general 'rules' of how to do so. I was very much still a rookie and will accept it could have got a lot more intense, however - the problem was that with my lucid dreams, I also had a lot more nightmares - including some experiences of light, yet still very terrifying 'Sleep paralysis'.
For instance, some days I remember I would sleep and have a little control over my dreams. I remember once I was at a pool party and everything was great and even was able to walk on the ceiling like Lionel Richie once which was a great experience. However, for every few great experiences, I suffered. I'd never had such bad nightmares before, and after stopping lucid dreams so did the nightmares - so I assume they're linked.
Basically, I vividly remember being thrown around my room by a ghost, feeling very tight-chested and even seeing a creepy Japanese girl in the corner of my room like the Grudge. Sometimes I could stop these bad dreams by realising I was in a dream, but it was still scary. Others, I would know I was asleep, and couldn't escape which was equally as bad.
It would be great to get back into it but I'm happy with the theory of 'ignorance is bliss' for now
