My paranormal story

My grandfather was born in 1943 in downtown Monterrey. Back in the day, houses used to be really big so after my great grandfather died, my great grandmother decided to split the house in two and rent   the other half. Shortly after, a family move into the house and the first impression my grandfather had about them was not the best. They were a young couple with a young daughter and my grandfather says that the girl was a little creepy. She was a more reserved kind of girl and for the 5 years that they lived there, they never really bonded even though they were both 6 years old. One morning the girl got really sick and died in her own room, obviosuly the parents were devastated and they left the house immediately. Shortly after they moved out, my grandfather was asked by grandmother to help her clean the house for the next renters. When they got there, the house was empty obviously, but there was a very odd thing at the girl's room: a gun safe. This gun safe was really tall and a young kid like him could fit perfectly in it. He was really interested in the mechanics, so he instantly went to play with the gears . He went over the house to play with the safe everyday since, and he would get more and more interested each time. Until one time, things were different, he went over the house as usual but by the time he got there he decided he wanted to get inside without closing the door completely. He got inside and left a small gap for him to be able to move the hinge, but he was not scared to get locked in because the only way for the safe to close was to move the hinge all the way to the way to the top. While he was playing inside the safe box, he suddenly heard a "click" and when he tried to push back the door he was trapped. While he was freaking out he realized that in order to think what to do next he had to relax. After he calmed down he started moving the gears just the way he had for so many times, and it just turns he remembered way too well because he was able to unlock the door from the inside. After he got out he realized that the house was empty and up to this day he does not know how the hinge moved all the way to the top.