Where, as Yubaba's apprentice, did Haku sleep? Where was his room?
Since we never saw it (at least in the English dub), I would think that it would be at the bathhouse's top level, somewhere in Yubaba's enormous living area, in a specific room just for him, similar to how she had rooms just for her office and for her baby Boh. As her apprentice, Haku got special treatment and was called "Master Haku", so he most likely didn't sleep with a bunch of the other main employees, like Lin and Sen did in that crowded room.
Where do you think his room was?