On the verge of bankruptcy, a crazy funeral home director goes on a killing spree and starts killing of residents of his sleepy little town to increase the need for his services.
What I like about this idea is that it could go many different ways... he could just randomly kill people he happens to come across or he could only kill people in town who had deep dark secrets themselves.... OR, muah ha ha ha!!!... he could turn around and sell the bodies that are supposed to be cremated to research labs for reanimation. [that just gave me an even better idea...]
[ADAPTED] This is not totally original. I remember seeing a similar idea somewhere on my search for creativity. Though I cannot tell you where or even when I saw it, I can tell you that either way it was up for adoption by someone at some point. However, there are no exact details and is just a broad idea that can be done a million and one different ways.