Reddit mentions of Hallucinations

To go further, it's normal to hear voices depending on the circumstances. Oliver Sacks covers this in his recent book Hallucinations

Whether or not these voices are interpreted as supernatural in origin is due to cultural or personal biases.

You would appreciate anything by Oliver Sacks. He was a celebrated neurologist who wrote a bunch of great books about consciousness and fascinating stories about conditions he saw in his practice from a very philosophical rather than strictly clinical point of view. You could start with The Man Who Mistook His Wife for a Hat, Hallucinations, or Awakenings. He gave a nice TED talk if you want to get a taste for it.

These sound like pretty normal hynagogic hallucinations to me (they do not have to be associated with any sleep paralysis).

However, I am not an MD and do not specialize in sleep disorders. A sleep study as others have suggested is a good idea... since you're in the Boston area, here are the major sleep centers in Boston, and here is a website where you can search for other accredited sleep centers.

I also second the recommendation for Sack's book Hallucinations to get some probably-reassuring perspective on how common hallucinations really are.

As for the 3AM thing, it's likely just coincidence (and your mind 'dismissing' times when you've woken at times other than 3AM), but another thing to check is if there is something that is happening routinely at 3AM that might be waking you. As a kid I always thought it was weird that I woke up at 2:14 every night, until I finally figured out that this was the exact time that a really loud cargo plane flew over my house every night (lived by the airport). Maybe a train going past, or a neighbor leaving for their morning shift, or the heat clicking on in your building, etc. More plausible explanation than the supernatural, at least! ;)

You're right that hallucinations come in many forms and manifest for a variety of different reasons that are not "psychiatric" in their origins.

The late Oliver Sacks' book, Hallucinations, really opened my eyes to this.

Nope.
You should read Hallucinations by Oliver Sacks.
http://www.amazon.com/Hallucinations-Oliver-Sacks/dp/0307947432

Ok not a documentary, but this book has been pretty crucial to my understanding of the weird and paranormal.
http://www.amazon.com/Hallucinations-Oliver-Sacks/dp/0307947432/ref=sr_1_1?s=books&ie=UTF8&qid=1405276511&sr=1-1&keywords=hallucinations

> Interesting. I never knew that was considered a migraine.

You too should really read (or listen to the audio book of) "Halucinations" by oliver sacks.

http://www.amazon.com/Hallucinations-Oliver-Sacks/dp/0307947432

Migranes are a considerable part of the book and are explained quite well.

Somewhat off topic, but I recommend checking out the following (non-Scientology) books which might help you understand what people with some types of dementia may be experiencing. Often people reach out to things like Scientology because they lack people to talk to that they can actually relate to their experiences - or even people that will listen with an open mind.

• Rethinking Madness by Dr. Paris Williams - this is an academic quality work, btw, not some crazy person rambling (that's important to me)
  
  
• Hallucinations by Dr. Oliver Sacks - a neurologist who has written several popular books about unusual neurological phenomena