"Old Black Witch" is a wonderful children’s book from 1963 written by husband and wife team Wende and Harry Devlin. It is a story about an old witch who haunts a tearoom! She doesn’t much appreciate the mother and son who decide to convert her old New England house into a tearoom, and she wants them out of there! But in the end, the unlikely trio combines their efforts.
This is a highly collectible book, no longer in print. Available from Amazon (purchase here), eBay, or perhaps from your local library. Definitely worth a read- and not just at Halloween!
P.S. There are 2 sequels: Old Witch and the Polka Dot Ribbon (1970 - purchase here) and Old Witch Rescues Halloween (1972 - purchase here).