Recently I visited my grandmother with a few family members. We stayed at her house for about a week. While we were staying with her there were a few strange occurrences. The biggest thing I feel I should stress that these aren't threatening or scary. Just phenomena that none of us who experienced them could explain. I'll talk about them in chronological order, so I don't confuse myself. I will also mention the layout of the house before I really get into it.
Off of the driveway is the side door. The side door opens to two staircases. A small one directly in front of you and a set leading to the basement. Just inside that door is a doorway to your left leading to the front room and the living room. Moving forward you can see the kitchen on the right and a small bathroom ahead of you. Heading to the right down the hall is a guest bedroom that connects to the living room. Continuing down the hall is the master bedroom and through that is a small sun room with a couch and a chair.
The third night was the night of the first occurrence. Everyone (besides my younger sister) had just gone to bed. My younger sister wasn't asleep but she had gone to bed before everyone else. We all had been laying down for about 15 minutes when my father and stepmother heard someone walk past the end of their bed and through the bedroom. I was laying on the couch in the sun room with my headphones on. The sound of footsteps continued on into the kitchen where they heard someone banging around. My stepmother swore it was me and waited for me to come back. But I was in the sun room on my laptop. Unbeknownst to my stepmother, my younger brother heard whatever it was enter the kitchen and then pass through the closed door that led downstairs to the basement, humming as it went.
The next night I woke from an unsettling dream to a sound of a thump. I rolled over and looked through the bedroom to the doorway that led to the hallway. I saw a figure standing there that looked in stature to be my younger sister. I rubbed my eyes and blinked and it was gone.
Nothing else happened until the night before we left. My grandmother had two electric candles that flickered like real flame. One was sitting on the coffee table in the front room and one was in the living room. My little brother was sitting on his inflatable bed packing. Me, my father, my sister, and my stepmother were all out back. My grandmother was off visiting her boyfriend. After about ten minutes of all of us sitting back there Damian came out with a strange look on his face. "Did any of you come and switch the candles on when I wasn't looking?" to which we all replied, "No, we didn't. Why?" He stated that when he looked up the one in front of him was on and the one in the living room had switched on as well. The candles had a switch on the bottom of them that made an audible click.
All in all, none of it was scary. Just a bit unsettling. My grandmother reacted the worst, saying "There's no such thing as spirits. It's Satan, the demons messing with us." Which I felt was a bit ridiculous, but to each their own I suppose.
I go with BadJuuJuu that the spirit is not harmful. It just tries to draw your attention, that's all. If your grandmother is not a believer, why don't you find out the history of the house, ask her neighbours about it. It could give us some clues about the spirit that is in her house. If you could possibly find out, then post it.
Regards and respects to you.