When you think of Steampunk, it harkens back to the era of Victoria. The streets were dark, lit by sputtering gas lights. There was a dreariness to the London air enhanced by the coal dust and damp which created the infamous "pea-soup" fogs.
So...is it any wonder that the era also abounded with mediums and spiritualists? Ghosts were very real to the denizens of Victorian England. Remember, this was the heyday of the post-mortem memorial photo. The science of photography was not something everyone carried around in a smartphone. Photographs were fairly expensive, and time-consuming. Sometimes the photo of a dead child was the only representation of them that a family would have.
The desire not to lose all connection to their loved ones kept many a spiritualist well-fed and dressed.
Steampunk seems an ideal genre to marry with this era of mysticism. Imagine a steam-powered magic lantern device that could project the image of a deceased loved one -- and how that loved one might be angered if the medium tried to cheat those left behind.
Or perhaps a safety-coffin goes horribly awry. The "deceased" could be relying on rescue -- literally being "saved by the bell," and instead finds themselves buried alive with no hope of escape.
A couple of free story ideas for you. Now someone go and write me more submissions for Ghosts, Gears, and Grimoires! The pickings have been thin so far. If you've forgotten the guidelines, check them out here.