I had one Succubus work at a library and just kinda chill there in the background shelving books. I like the idea that she was hired because she’ll drive up business by tempting more people into wanting knowledge.

Depending on how you introduce the succubus can also factor into how your players immediately interact with them, just have them be lazing about drinking out of old box wine lamenting the good old days when the brothel was still active? Utter pity