I've been doing some testing. It might just be in my head, as said before, but it seems like there's more activity when I do certain things. For example, having either a lot of lights on or no lights on both seem to cause the activity. Having just 4 or 5 seems fine.
The louder I am downstairs, the more obvious the panic presence is. If I'm dead quiet it's just a little nagging itch at the back of my head telling me I'm not welcome the entire time until I'm back in my room. If I'm loud, it'll make me feel significantly less uneasy until I get to the stairs when it becomes blinding "GET THE FUCK OUT".
The black mists are connected to low light. If it's too dark they won't appear (or maybe they just blend in) and if it's too bright they won't appear. The smells and sounds are connected to people in some way. If more than one person is awake, the smells appear. The sounds only occur when one person is awake and are at their peak when that person is trying to sleep.
The apparitions are mostly unconnected, but they appear MOSTLY either at early morning (like just before dawn) or dead middle of the day, always up stairs and usually near the stairwell. They are ALL faceless, headless, or in one case without anything above the waist. (Though my mom said she recently saw one with huge black stitches all over the blank face, I don't buy that because it doesn't fit the pattern and sounds like fucking Silent Hill. Plus I haven't seen it.) They appear in predictable patterns, but they seem very aware. I had the misfortune of being menaced into my room by a headless man earlier today, for example, who then slammed the door shut.
Mostly I've felt rather safe in my room, which is why I've been ignoring this. It doesn't seem as important so long as I have a Safe Place, which was being violated strongly when I posted this.
For the curious, I've looked some of the stuff up regarding the history of the place. There WAS a fire, but no one was home when it happened. The history of the land is pretty vague, but apparently it was never much of anything until the county bought it from the land owner and turned it into a housing project. (Yeah, it's the projects. I'm poor, stfu.) The city DID have a lot of citizens involved in the civil war, but to the best of my knowledge there were never houses in the area of where I'm living until recent times.
I've also contacted some people in the "ghost hunting" field, and they're all telling me that it fits a "demonic" haunting. I'd giggle at them, except that faceless people in offensively formal clothing and things that are missing everything above the waist are fucking scary as hell and these "experts" all admit that they don't know what "demon" means except "definitely-not-human".
FTR, I don't really take ghost-hunters seriously but I DEFINITELY take ghosts seriously and these are different from all the hauntings I've read up on. (And if anyone knows of any similar hauntings that they've read of, hook me up, I'm interested.) That being the case, I say the ghost-hunter "demon" is as good a guess as anyone is capable of offering.