Why was Alice in the crazy house

because of her visions. She had them as a human too. James tells Bella about it in the Ballet Studio in the book.

She had visions as a human girl too, and her family thought she was crazy, so they committed her. Great family.. their loss, Cullen's gain.

Because to c visions in that era meant 你 were either posessed, a witch 或者 crazy.so her so called family "died" her ass, the 日 she was committed to the insano assylum.

She had premenitions. Her family made everyone she knew believe she had died and left her there. She was turned into a vampire there 由 someone else in the mad house to protect her from a vampire hunting her.