A terrible commotion in a rented apartment

I'm married to a military man, and due to his service, we frequently change residences. This terrifying incident happened in Stavropol over a year ago. At the time, my son was one year and two months old. We rented an apartment from some nice old people for, well, not much money. The apartment had three rooms, but one room was locked with the owners' belongings, so we were left with two rooms to use. The apartment was quite old, and the renovations weren't exactly the freshest, but it was livable. My child slept in one room, and my husband and I in another.

As I said, my husband is in the military; he leaves early and comes home late: he's on business trips, responsible, or on duty—meaning he often doesn't come home overnight. And then, literally a week after moving into the house, I started noticing something odd. I'm washing dishes in the kitchen, and out of the corner of my eye I notice someone standing behind me. I turn around—there's no one there. But a strange feeling remains.

And then it gets worse. My husband left for another training camp, leaving me alone in the apartment with my son. And then, literally on the third night, my child started waking up several times a night with a heart-rending scream. I'd never heard him scream like that before, even when he was very little, and something hurt. Naturally, I came over, soothed him, and he went back to sleep.

One evening, tired of running from room to room, I put my child to bed with me. That night, my son woke me up, but the strangest thing is, not with a scream, but with a whisper! A one-year-old child—and suddenly in a whisper! "Mom, Mom, Boba!" At first, I was half asleep and didn't understand what he was babbling, but then I woke up, more surprised than anything that he was whispering than shouting. And when I was fully awake, I heard heavy footsteps coming from the front door, as if someone had walked down the hallway past my room and into my son's room. The springs of the sofa where my son usually sleeps creaked, followed by a hissing or gurgling sound. Someone got up from the sofa, walked down the hallway, went into the kitchen, and approached my door.

To be honest, only sheer terror could explain what I did. I got out of bed, turned to face the door, and practically screamed:

"Get out of here! You won't dare harm my child. I won't give him up to you!"

After that, I heard another sigh, and footsteps heading toward the front door.

 I didn't sleep the rest of the night. True, that someone didn't bother us anymore, but we still moved out of that apartment before even a month had passed, leaving our money behind. And when I handed the keys back to the owners, they told me that none of the tenants had lived there for more than a couple of months; for some reason, they were moving out.