Re two or three ghosts in a story – there’s a lovely incident related in Tiffany Stern’s book Making Shakespeare, about rehearsal practices (p. 78). Actors learned their parts in isolation, and often did not know the plot of the play they were in. Two ghosts had (separately) performed their parts fine in rehearsal. On performance day, each one peeped through the hangings of the scene, saw a ghastly white face opposite, and was so frightened he refused to go on stage.

Penny.