Here is a news story about a lost cemetery in Florida. Seems it was a known burial ground at the time it was active, but then because it was black immigrants buried there, it was never marked or preserved. Now there's a company trying to build low-cost condos and apartments on the site. There's a lot of background material that can lead to stories of their own. The most obvious take is a version of Poltergeist, but I think you can do better. The thing I get from the article is that the people just want to be remembered. There's a story line with the cemetery when it was active, that would be cool as well. Florida as frontier.
Just as an aside, please don't go in the direction of the "magical negro." Nobody needs that anymore ("Oh Brother Where Art Thou" got away with it because he's actually the Oracle of Delphi).
I love cemeteries. I've visited a lot of them around me and have taken lots of photos. Martha's Vineyard has several burial grounds. Some of those only have one or two stones left. The public cemetery at Gettysburg also has some great stones and interesting history of it's own. There's a lot of things you can do with cemeteries beyond the traditional ghost story.
Anyway, as I read that article my "writer sense" was all a tingling. Hopefully it'll do the same for you.