That's his office, back of Saint Mike's.
4 seconds sound clip from the The Exorcist movie soundboard.
You can hear this line at 00:40:33 in the Blu-ray version of the movie.
Quote context
[...]
- Over behind the church. You know where I mean over there? It's a red brick wing. Saint Mike's.
- What goes on there? Who's the priest I keep seeing there? He's there all the time.
- He has black hair and he's very intense looking. Who's that?
- That's his office, back of Saint Mike's.
- He's our... Our psychiatric counselor.
- He had a pretty rough knock last night, poor guy. His mother passed away.
- She was living by herself and... I guess she was dead a couple of days before they found her.
[...]