Wow I am surprised. I was going to post the local legend about our oldest church and found that it has a wiki page that mentions the witch's grave:
https://en.wikipedia.org/wiki/Old_St._Thomas_Church
It however does not tell the story. If you walk down the walkway to the church, on the right there is a blackened grave stone of a woman. I found this blog which has pics of the grave stone as well as the local lore and the truth.
https://explorationproject.org/witchs-grave/
The truth as I heard it. - apparently the minister of the church was a very eligible bachelor and all of the women were very interested in catching him. The woman who did become his wife was labelled as an outsider, a mean woman and subsequently a witch simply because of jealousy. Small towns.
So not really a scary story, only small mindedness.