Do you believe, and if you do what are some of your experiences?

My mom has told me stories (at an appropriate age) of her "encounters". One of them is when she was living above a small store in Minnesota and after everything is closed, being up in her apartment..and of course alone. She had double bolt locks on the think door and always made sure to lock it. She was home one evening and she could here footsteps coming up the stairwell. The steps, covered in black rubber, made a squish and squeak with any footstep. As she peered around the corner of her kitchen she could hear footsteps coming further and further up, till they reached her thick front door. She went over and looked through the peep hole to see if anything was there, but she couldn't see anything. After standing there, face pressed against the door, searching the stairwell.. she sat back down. Only a couple minutes passed when she heard the footsteps again. But this time she didn't get up, the footsteps became louder and squeaked with each step and then a thud at the door. She said she could hear the locks being messed with so she went to look one last time. When she looked she saw nothing. But she knew she wasn't alone.