That would depend on the school. I know that at my child’s BS the theater faculty email addresses are easily found in the arts->theatre section.
When you are at the point of having something worth asking, that is not easily determined from the school website, and is beyond the scope of the AO’s knowledge.
In fact, I would contact the AO first with questions. While I understand that you want to impress upon the schools that you are applying to that you would be a fantastic addition to their student body, and that you are enthusiastic about the performing arts, unless you are applying to a school that is exclusively devoted to the performing arts, the faculty will have little weight in admissions decisions.
If you schedule a campus tour, make sure that they know your interests when you schedule it.
Caveat: make sure their theatre program is a good match for someone like you. Theatre programs can be VERY personality driven.
When I was in prep school, the head of the Drama Dept. had a near cult like following. However, those who didn’t fit into her cult were frozen out. A former classmate bitterly bemoaned that his single parent mom had made great sacrifices to afford him the opportunity to attend this prep school, only to not be able to benefit from the drama program, because he didn’t have that right “something”. He is listed among the school’s “Notable Alumni” in Wikipedia as an “actor, singer-songwriter” - he succeeded, after being ignored by the prep school’s drama dept.