I know there are several 'Spike as Buffy's bodyguard' fics out there. I'm looking for one that I read a few years ago that I can't seem to find. Unfortunately, I don't remember all that much about the fic, but what I do remember...
It was All Human. No vampires, no slayers. Neither Spike nor Buffy turn into a vamp or a slayer.
Spike isn't really just a bodyguard, I think he was more like a gun-for-hire. I think he'd just come off a job and was supposed to have some down time. He didn't want to take the Buffy job cause he usually did more 'difficult' cases, but I think maybe no one else was available.
I believe Spike had a fancy apartment up high in a nice building. I think he didn't use it much cause he was mostly gone on jobs. He takes Buffy there at some point, maybe when her place isn't safe?
Sorry I don't have more to go on, as I said, it's been a few years since I read this fic. It's really been bugging me lately, so if it sounds familiar to anyone let me know!

Thanks!!