SOLVED. It was about a girl who worked at a library/museum, but instead of books, and instead of just looking at things, you could get them out. [s]

[Maryanne]

There were rooms full if normal things, like wigs or puzzles, but for the employees, there was a room full of fairy tale objects, like the flying carpet, or bluebeards key.

[Andria]

Sounds like The Grimm Legacy, by the delightful Polly Shulman

[Maryanne]

YES! thats it! thank you!