Strange occurrences in an elderly woman's apartment

Old people, especially sick ones, often get all sorts of weirdness coming to them. My grandmother lived alone in an apartment, and over the years her mind started to slip. She'd tell us that a neighbor came to her at night and stole things. Like, she hears the front door open, then footsteps. But she either can't get up and look, or she falls asleep. She calls me and my mom all the time. One thing or another has gone missing. She asks us to come over and find it. We'd come. Things would turn up in strange places sometimes, but overall, grandma could have put them there herself and then forgotten. Once my cousin came over to look for a missing wallet. First thing he checked was the linen closet under the stacks of clothes — grandma used to often put money there. He checked several times, thoroughly, as he said. Not there. He ransacked the whole apartment — nowhere. He decided to check that closet one more time. He put his hand under the stack and pulled out the wallet. He swore afterwards that there was definitely nothing in that spot. Then there were other small things. Honey in a jar on the mezzanine, where grandma herself couldn't possibly reach, turned up eaten, and the caregivers all left. They didn't give a reason, but one of them dragged in icons from somewhere and set them up by the bed where she slept at grandma's. Grandma also complained about knocking on the wall that kept her from sleeping. I heard that knocking myself once, like someone slammed a sledgehammer against the wall.

But that's still okay. One time my mom and I come to visit grandma, we ring the doorbell, grandma is fumbling with the keys behind the door, can't open it. And then my mom and I clearly hear a young woman's voice from inside the apartment. Mom and I exchanged glances, decided that a neighbor had come to visit, there was one like that, young. Grandma finally opens the door, we go in, and there's no one in the apartment. We ask grandma, she's confused. Well, okaaay. We made food, were about to sit down at the table, and it turned out grandma had run out of some pills. I dashed to the pharmacy. I come back, mom calls me to the balcony. She says she was setting out plates in the kitchen, grandma was in her room measuring her blood pressure, and then there was a voice. A nasty old-womanish one, it sharply said some phrase loudly. Mom immediately ran in to grandma, she's sitting there unperturbed, doing her thing. What the hell, like. And here's the juiciest part. We sat down to eat and grandma tells this whole story. Yesterday evening, she says, it was already late, someone rang the doorbell, she opened it. On the doorstep were two women, one older, one young, asking to stay. Well, says grandma, I let them in. When asked where they went, she said they seemed not to have left, kek. And where are they now then? She blinks and shrugs — they seemed to be here. So that's how it is.