yes, it was Salazar who built it. Alright, so Mytle didn't handle the book at all, but because the book was thrown through her head, she got all mad and turned on the taps, right. But how could she've done that, when in the book, the ghosts float right through the food, and people can walk right by them. Also, if the book flew through her head, then it shows that things go right through her, which would mean that the tap handles would too.