Speculative Fiction: Ghost Stories and Pirates of the Caribbean

                 Not going to lie this one threw me through a loop, it took me a bit to realize how broad of a subject it is, and that so many stories fit underneath its umbrella. However it seems that a large prevalent part of it is the supernatural and fantasy involved with the super natural. Ghost stories of any kind fit into Speculative fiction by being a fictitious element within our reality that follows a separate set of  rules then the rest of the world. I think that if this is the requirement for speculative fiction, then shouldn't any story that involves a fictional world element that interacts with our world but follows its own set of rules be speculative fiction, even if it's a whole separate world? So a world like Pirates of the Caribbean which takes place in our world, our version of the world but also has an entire separate world of fantasy, magic and myth connected to it, but it follow its own separate world rules then the ours even though it interacts with us? With that logic as well wouldn't a story like Harry potter also fit into this category as well? It is also a fantastical world that interacts with ours under separate set of world rules, or am i just being and idiot and confusing myself? I guess we will never know.