I'm a sceptic.
But I've had déjà vu for years. I'll remember hearing conversations or witnessing my visual surroundings as if it had happened years ago but in fact it is happening at that very moment. Once it starts, I can see the 'memory' playing in my head to which I can usually predict what will happen next with surprising accuracy. It never lasts long and it's usually about something trivial. The longest one I had lasted for a minute and it included visual and auditory memory. The more I have them the better I have gotten at 'predicting' what will happen immediately next. It's a trippy experience to say the least.
Possible explanation from Wikipedia: Scientifically speaking, the most likely explanation of déjà vu is not that it is an act of "precognition" or "prophecy," but rather that it is an anomaly of memory giving the impression that an experience is "being recalled." This explanation is substantiated by the fact that the sense of "recollection" at the time is strong in most cases, but that the circumstances of the "previous" experience (when, where, and how the earlier experience occurred) are quite uncertain. Likewise, as time passes, subjects can exhibit a strong recollection of having the "unsettling" experience of déjà vu itself, but little or no recollection of the specifics of the event(s) or circumstance(s) they were "remembering" when they had the déjà vu experience. In particular, this may result from an overlap between the neurological systems responsible for short-term memory (events which are perceived as being in the present) and those responsible for long-term memory (events which are perceived as being in the past). The events would be stored into memory before the conscious part of the brain even receives the information and processes it.
Other possible explanation: Perhaps having a well developed Ni, will in fact, make you psychic.
As for ghosts... I used to be very creeped out by this one room I slept in as a child. I always felt like something was in the room with me, watching me. I would often stare into the mirror across from the bed, looking past my own reflection searching for that 'something' that was watching me in the room behind me. My focus always came to the bed. Many, many years later after the house was long sold I learned that in the 1940's, my grandfather's first wife DIED on that very bed, in that room, with all that same old furniture, including the mirror.
Possible explanation: The first thing that comes to mind is that I always felt some degree of being watched in that house because the rules were rediculously strict. I was constantly sneeking around to give myself some freedom. So it's likely for some reason I associated bad, 'creepy' feelings to that room since it was the room I was allowed to sleep in but not claim as my own. Technically speaking it was a guest room but I felt more like an intruder than a guest. The part about someone dying in that room could be mere coincidence. Not to mention I was a little kid with an imagination.