I've had this happen twice so far; it usually happens when I didn't get a lot of sleep on the previous night.

What happens is I randomly start viewing a dream, but only for a few seconds and suddenly I faint in my dream. Last night (the second time I had it), I heard a weird cackling laugh as I *fainted*. Once my eyes in my dream shut I think I went into sleep paralysis and suddenly hear these ?magnetic? waves. I think this is really light as I can wake up with willpower. Anyways, what can I do at this point in regard to lucid dreaming? If this ever happens again what could I do to take advantage of it?