>>42529804gym is an abandoned 'haunted' house, but not like a circus haunted house or anything, just a normal rundown creepy house at the foot of an even creepier forest.
the lore is that its not really a haunted house necessarily, but is just an abandoned house that the gym leader stays at and takes care of ghost pokemon in.
the house is somewhat big and open, but its really dark so you can't see too far ahead, and has a lot of interact-able objects.
the objects give you hints on if you're going the right away or how to progress.
There are no trainers, but the objects you interact with will sometimes trigger wild pokemon battles, like you interact a table that has a tea set on it and fight a sinistea or polteageist, you interact with a candle and its a litwick, and there's even a golurk "statue" that comes to life and fights you in a double battle where it has a honedge. I'm also thinking there'd be several interactable candles to help you see around the open house, but theyd often be wild litwick, sort of doubling as a hint and a battle instead of just being one or the other.
i like the idea of being the seventh gym.