Yes and no. Right now the supernatural market is pretty saturated. However, there’s always room for a breakout story. You’ll need an original approach – something that slices through the ordinary.
My best example of that isn’t a book but a movie. On the surface Spirited Away is simply a ghost story. But it’s so original it’s difficult to place it under a specific supernatural heading. It has witches, dragons, plenty of ghosts (or… are they?) time travel (maybe) and a Radish Spirit. It’s worth watching under any circumstance, but especially if you’re looking for a way to market the supernatural.