Ghosts and a Culture of Imaginary Spirits

I recently had a friend tell me that a ghost used to haunt her house.  The ghost knocked shampoo bottles into the shower, and her young son told her the ghost's name was Bob.  He walked around and around the circular porch at night.  So my friend and her husband tore out a portion of the porch so the ghost could not walk all the way around it anymore.  I have to say I laughed a lot when she told me this.  

Does anyone else see flaws?  Even if there were a ghost, taking out a portion of the porch would do nothing.  The ghost could float across, or he could walk on the grass.  Yet, these people actually ruined their circular porch to ward off this imaginary ghost, and I guess it worked!  He no longer bothered them!  Imagine that! 

Don’t you feel if you were a ghost you would do a lot more than knock over shampoo bottles and walk around outside?  I would be whispering mean things in a person’s ear, taking away their food when they were about to have a bite, throwing things in their paths – oh, there is so much a ghost could do!  

Why do they not realize that the ghost is culturally taught to them?  Animals do not have ghosts that haunt them; why do only “the smartest species” have all these mental issues? 

I tried explaining to my friend how ghosts could not remain in the room due to our physical laws of the universe, that a ghost with no matter and no mass would be whisked away at tens of thousands of miles an hour due to the laws of gravity and the earth’s rotation around the sun, but she just claimed it was there – she heard him.