Hearing footsteps going up and down stairs

This was around Halloween last year. I live with my dad in my late grandmother's house. Around 2-5am every night for a week or two, I would hear footsteps walking around the house or sounding like someone walking up and down the stairs. I was caring for my dad who has cancer, so I would get up to check on him thinking he's awake. He would be sound asleep every time.

I told my dad I was hearing footsteps and coming to check on him only to find him sleeping, and he said "No way! I heard footsteps and got up to check on you, and you were sleeping." So we were both hearing it.

After a couple nights, I would hear footsteps clearly going up and down the steps and could hear them upstairs right above my room. It sounded like heavy boots walking around. It didn't feel evil, but I couldn't sleep out of fear. I do not think it was my grandmother before anyone suggests this.

After around a week of this, I was upstairs taking a bath late at night. I once again clearly heard someone walk up the stairs and walking around outside the bathroom door, to the point I was sure it was my dad, but part of me was too afraid to call out and see. I then heard the cabinet door we have outside the bathroom open and close with a bit of a slam. I immediately called my dad on the phone and said "you're up here right?" He said no? I said "then you need to get up here right now because something's up here." He immediately came and searched the room outside of the bathroom and found nothing.

I haven't heard anything since. This was the only true without a doubt paranormal experience I've ever had. This house has long had paranormal activity that I haven't personally experienced, but have heard stories from my dad and grandmother and their guests. Slamming cabinets and doors for the most part. Finding all the kitchen cabinet doors open.

I still wonder why it just stopped. It was around Halloween, so maybe that gave the "spirit" more energy. I do still experience sleep paralysis and nightmares almost every night, however. Just wanted to share.