When my son was 2 1/2 (he is now 9), our family moved into a low-income apartment which was set up much like a standard townhouse with an upstairs where the three bedrooms and full bath were located, and the downstairs included the kitchen, living room/dining area and small powder room.
At first, everything seemed quite ordinary. My husband worked evenings, so my son, daughter (18 mos at the time), and I were on our own each evening until about 11:00 pm. My son's room had a baby gate in the doorway to keep him in, but so I could still hear him if he needed me. My daughter had her own room and slept in her crib. My (now ex) husband and I began noticing that Dominick was talking to someone each morning. We would lay in bed of a morning, listening to Dominick chatter away in his room, and joke about his "imaginary friend".
One morning, I sneaked quietly to peek into his room while he was talking so animatedly. My son was sitting on the floor holding one of his toys looking directly in front of him as though someone was sitting right there with him. He was showing his toy off to this invisible person while saying, "Look, Papaw!" Papaw is what Dominick called/calls my father, his grandfather, but at that age he called any man from about the age of 45 and up "Papaw". He seemed to think that term was just referring to older men in general. Seeing him so obviously speaking to someone as if they were flesh-and-blood while I saw nothing sort of creeped me out, but since he seemed happy enough, I thought nothing of it. We even started referring to it as Dominick's "ghost friend" at that point.
One day, when I came up to get my son up from his nap, he was already awake standing at the doorway. He excitedly pointed DIRECTLY BEHIND ME at the top of the steps and said, "Look, Mommy! Papaw!" It took all I had to actually turn around and look. I was certain "something" would be right there. (Thankfully, at least in my opinion, I saw nothing.) Again, I took it as he was seeing someone who was no longer there, but that this person seemed to make him happy so I wasn't too concerned.
A couple of weeks later, I put Dominick to bed. His sister was already asleep in her own room. From downstairs I could hear him chattering away as usual to "Papaw". (Dominick was a rare type of toddler in that he would only go to sleep if you put him in his room and left him to climb in bed when he was ready.) As I said, Dominick was in his room, not yet asleep, doing his usual of playing a bit before he crawled into bed. I could clearly hear him awake and talking happily to his "ghost friend". Suddenly, my son let out a scream like I've never heard before or since. When someone describes a blood-curdling scream, that was it. When you are a Mommy, you learn to differentiate between your child's cries (hungry, wet, hurt, tired, etc.). This was pure terror, nothing else.
I rushed upstairs and grabbed my trembling and sobbing son. He slept in nothing but a diaper at that age, so I quickly checked him for some type injury. There wasn't a mark on him. His room was child-proofed to an almost ridiculous level, so there wasn't actually anything to hurt himself on in the first place. I have never seen my son so scared in my life. I was so angry that I yelled at "Papaw" to never bother my son again, and grabbed my son and daughter to wait downstairs until my husband got home from work.
We immediately moved my son out of his room (as that seemed to be the main place he saw the ghost), and down the hall to share his sister's room. At first, it seemed to do the trick. My son no longer talked to anyone who wasn't visible, and he had no more scares. Unfortunately, it didn't last.
After my husband left for work of an evening, I didn't even venture upstairs, waiting until my husband got home to put the kids to bed, because I suddenly started to hear someone walking upstairs at night. This was different than the noises you hear from the adjoining apartment units. This was footsteps squeaking the floorboards, going into MY bedroom (which shared no adjoining walls to other apartments) and walking around our bed to MY side of the bed and back...repeatedly, until my husband got home. As much as my husband hated it, I started sleeping with the TV on for a night-light, just in case. Still, I took comfort in the fact that my son seemed to be free of the ghost.
One day, a few weeks after moving my son into his sister's room, I had put them both upstairs for their nap (the hubby was home and it was daytime, so I was brave LOL). Right after I got back downstairs, I started hearing music playing from their room. I went up again to see what it was and found a toy in a bin at the top of the closet (that was far too high for either of them to reach). This toy had been a part of Dominick's Exer-saucer/Baby Walker that he hadn't used in well over a year. I assumed the batteries must have been dying, causing it to play on its own. I even pushed the button that activates the music, and found that it wouldn't start up. Satisfied that the batteries had just had one last hurrah before dying, I put it back in the bin and went back downstairs. Yet again, as soon as I made it down, the music started. I went back up, grabbed the toy and brought it downstairs with me, still figuring it was the battery. The whole time the kids were napping, I had that thing right on the counter near the couch. Not so much as a peep. I pushed the button. Nothing. I decided to try putting it in the room again, as a test, I suppose. When I went to get the kids up from their naps, I dropped in back in the closet bin. No music was heard the rest of the evening.
That night when we put the kids to bed, almost as soon as Dominick was in the room and we were in ours, the music started playing. I had my husband take the toy and throw it in the garbage immediately. It went straight to the dumpster the next morning.
We only lived there another couple of months, and for the most part it was only the footsteps at night from that point on. I was never able to find any history about that particular apartment (i.e. Deaths or suicides), but the town itself supposedly has a history of Native American burial mounds. The property itself had no real history though, as far as I know, other than being a pasture for cows previous to being developed.
As for my son, he hasn't ever had any experiences like that since. He is a very sensitive child, though, and has an almost spooky sense of reading people's true character when he meets them. He can sense a "bad" person from the get-go. He can also sense if someone is sad or upset, even if they appear otherwise.
I have asked him (without trying to reveal any details or frighten him) if he remembers anything about our old apartment, or anybody at our old apartment. He says he doesn't, which might be for the best, although I wish so bad he could tell me what happened when he was so frightened that night. One day, I hope I can find something that explains who my son was seeing.