Ruth is a psychic who helps ghosts resolve the issues which keep them bound to the material world.
Once these issues are resolved, they can finally head off into “the light.”
“The light” used to refer to Heaven, but escorting ghosts to the hereafter doesn’t pay jack squat.
Now, Ruth puts ghosts into antique lanterns and sells them as emergency battery-free lighting.
I’m sure you wish that Granddad or Aunt Sue were at peace up in Heaven, but you must admit that the stairs to my root cellar are rather peaceful too, right?
I even oiled the stairs. No creaking.