It might not be that. It doesn't look nearly as much like bleeding as whatever's happening here, I have to say. Even if a spirit manages to look like a living person it only goes so far. I also don't know what the wraiths would be, in this scenario.

[But it's certainly what comes to mind, knowing that they are already dead.]

Probably a good idea. I'm reluctant to just tell everyone this spirit-motes theory without a bit more information.