FOUND - I had the roles switched. Cas is the actor and Dean is the bodyguard. Fic is called The Bodyguard (Duh!) Here’s the link
https://archiveofourown.org/works/20553779/chapters/48789569 I’m looking for a specific fic set in a Human/Modern Setting/No supernatural Au.
Dean is an actor on a TV series (soap opera, I think) who has been receiving weird/creepy/threatening fan mail recently. His agent/manager (maybe brother) hires a private security firm to protect Dean and track down the crazy stalker. The firm assigns Castiel as his full time bodyguard. I think Charlie is the firm’s tech guru and Kevin is one of the techs (evidence, prints, etc.) Cas moves into Dean‘s loft and Dean hates the intrusion. He tries to convince Cas that he doesn’t need protection or tries to get him to quit by being uncooperative. The letters get more threatening and a dangerous package is left at Dean’s door. They’re slowly attracted to each other and eventually act on the feelings. I think something happens where Cas loses Dean briefly and then gets reassigned to guard his co-star instead of Dean. They find a way to keep seeing each other and ultimately the stalker is caught.
That’s all the detail I remember. I’ve tried searching multiple tags and keyword, but I don’t think the author used many other than just character tags.
FYI - I already found “Guarding Dean” and that is not the one I’m looking for.
UPDATE: I also found The Lives We Leave Behind and that is not the one I’m looking for either.