From reading about haunted castles and abbeys just recently, it struck me that the stairway is very often the hang-out of choice for ambitious apparitions who want to see some proper hands-on action. I was particularly interested to read a story about Airth Castle near Falkirk, whose phantom dog lurks in a hallway and has a habit of biting people’s ankles.   Believe me, I would soon sort him out.   A fistful of needle-sharp claws in his nose, and he’d go whimpering off back to his grotto. But the idea of haunting a stairway got me thinking.   I love stairs myself, and there’s usually a lot of fun to be had on…