Annoying phone calls

My mother used to have a friend, and I remember she would always come over and tell us her creepy stories. I was little then and was terrified of her stories, and my mother would always tell them five times...

Basically, the phenomenon boiled down to the fact that her doorbell suddenly started ringing for some unknown reason. Everyone in the apartment heard it, so the theory that it was hallucinations (schizophrenia, delirium) is ruled out. The calls started in the evening, when it was still light—usually right after sunset. At first, the woman kept calling "who?" at the door for a long time, and when no one answered, she finally opened the door and went out onto the landing: everyone was home, there was no one to be afraid of, maybe they wouldn't kill her—the very flower of ordinary logic. Of course, there was no one on the landing. Absolutely no one. Then the calls started ringing in the middle of the night. They were faint. But no one went outside anymore; everyone knew it was "it" again, calling for some unknown reason.

The woman finally got fed up with this phenomenon, which had been going on for months, and went to some old woman, maybe a gypsy. The woman poured something into her water—wax or egg yolk, perhaps—and the woman (according to her own account) saw all sorts of creepy things in the glass. Finally, the gypsy woman told her that if "it" came and called again (especially at night), she should never look through the peephole: you might see something that could instantly turn your hair gray and give you a heart attack. I remember how my hair stood on end when she told me all this stuff about the calls and the peephole. Then the calls seemed to stop, and soon the woman went abroad—to Bulgaria, I think.