Do you believe in ghosts?

yes, i do believe in ghosts. Because 3 1/2 years ago , my dad died in a car accident. and my brother was in the car with him. but my brother was ok. and after my dad died, my brother started to see the ghost of my dad. and about a month ago, me and my bother went up north with my gradma. and when we were gone, my mom heard footsteps upstairs. so she goes to look, but no one was there. so she goes back to sleep and then she hears a door slam.... so yeah , i do believe in ghosts.