Witchcraft: a Primer
Ectoplasm, Cauldrons, and Graves, Oh My!
Tarot
The Geography of Black Lake
and twelve volumes of An Anthology of Banned Books.

You could read one of them, though your mission to escape this house could be put in peril if something were to catch you here. Then you spot one very familiar cover: it's the book you gave that ghost! You quickly take it off the shelf, fitting the loose pages into it, noticing only one change since you gave it away: a beautiful pressed flower in its middle.
Taking the book, flower and all, you notice one of the books next to it seems a bit... off...
You press the book into the shelf, and the whole shelf starts rotating! Cool, a hidden staircase!

You hear the door behind you lock, and trying to open it proves impossible. Your only option for a hasty exit seems to be leaving through the secret passageway.