Bit of a backstory here. I'm watching Lucy Worsley on TV and she showed us a mediaeval crypt in a Berkshire field.
It is the only rermaining part of Ladye Place, a mansion originally dating from the fourteenth century. The crypt was the site of secret meetings by plotters of the Glorious Revolution.
Anyway... I'd heard of Ladye Place from a book I loved (to scare myself with) as a kid, Harry Ludlam's awesome The Restless Ghosts Of Ladye Place.
So I did a little Googling and found the full text of the book online, with its terrifying first chapter all about, yes, a ghost in a theatre.
The Restless Ghosts of Ladye Place
I was really too young to read this book first time around. The image of Thorne's face gliding along the top of the stage gave me nightmares. I probably wet the bed.
Worth every minute. Now you, too, can feel the warmth.