(This first part isn't what freaked me out. Just something odd I noticed so I decided to include it).
So, I ended up taking several photos in the room with the mysterious floating box. Afterwards, I realize that I had only seen about half of the whole site the first time I was there, so I decided to walk around and check it all out. The first thing I notice is that there are a lot of worn down paths through the grass that connect several of the buildings. I didn't think anything about it at first. I just assumed that it was from children playing, homeless people, or maybe dogs and cats. As I'm walking around, I see a large building that I had not been into the first time. I am walking along one of these paths that lead to a door to the building. From a distance it is obvious that the path doesn't just stop at the door; it goes across into the inside of the building. Obviously someone has been going inside quite often. But, as I get closer, it is becoming very clear that the actual door has not been opened in years. There are vines that grow across the door and attach to the brick on each side. There are objects in front of the door that are covered with ivy. Maybe mice, or other small animals can fit under the door, but the paths are clearly made by something much bigger. Anyway, there may be a logical explanation, but I just thought it was pretty odd. Now to the part that freaked me out a little.
I had been at the old factory for a while, and just wanted to get a few more shots of the main hallway that connects most of the buildings before I left. Just as I take a shot I hear two men coming my way. They are talking very loud, and one of them was laughing. I figured they had seen me come in, and had come to run me off since there were several no trespassing signs on the way in. As they get closer I could tell that they were actually in the large warehouse type room right beside me. I was standing about 40 feet from the door that connects the warehouse to the hallway that I was in, and they were headed towards it. I go ahead and put my camera in the bag, and fold up my tripod. I start towards the door, but I wasn't paying attention to what they were saying. I was working on my story in my head in case they asked what I was doing there. I stop about 10 feet from the door and can tell they are about the same distance away on the other side. I am waiting for them to step out, and just as they are about to walk out of the door, the talking stops. It goes completely silent. I stand there for a few seconds waiting for someone to come out, but they never do. I finally walk up to the door expecting them to be just a couple feet away, but as I look inside, there is no one there. The room is empty. It's a good thing I had packed up my camera because it would probably still be sitting on the tripod in that hallway. I headed straight for my car, and didn't look back.
I tried to think of some explanations, and here are the 3 best ones I came up with:
1) a very good ventriloquist
2) talking squirrels
I had taken a photo earlier in the day of the same door, along with the hallway I was in.