Is this house haunted?

I think my Grandma's house is haunted. Things that never get used disappear and come back. My mother saw a shape like a human twirling something around. My mom also heard her sister (who died) saying her name exactly the way she used to say it. My grandpa died in the living room so it might be him and my aunt who are haunting it. Do you think that is enough evidence that ghosts are there? I'm kinda scared but I don't think they will hurt me.