Kay Mitchel has gotten a lot of funny mail as financial secretary for Potomac Presbyterian Church in Potomac, mostly the computerized kind from organizations that take the house of worship for a person.

Once, for example, Potomac P. Church was offered a sizable home equity loan from Merrill Lynch & Co.

In August, Mitchel received an application from Chase Manhattan Bank, offering Mr. Potomac Presbyt a pre-approved Visa card with a $4,000 line of credit.

Mitchel decided to have some fun and filled out the application with tongue firmly in cheek, figuring Chase Manhattan would get the obvious joke. She used the church's tax identification number in place of the requested Social Security number and added a zero to make it long enough.

For occupation, she put down "self-employed representative." Then, in the coup de credit, she listed "Calvin" as Presbyt's mother's maiden name, playing off the name of John Calvin, a 16th-century leader of the Reformation movement from which Presbyterianism sprang.

"I thought the bank would get it right away," said Mitchel, "or at least check it out and find it false."

Not even close. Within a week, Mitchel had a card issued to Potomac Presbyt. She used it once to see if it would work and has gotten a bill already. "It makes me wonder just who gets credit these days," she said.

Chase officials aren't sure how the glitch occurred but said a data entry clerk probably misread information from credit information firms and entered the name incorrectly. "The church itself probably had good credit," said Amy Sudol of Chase Manhattan. "And when the name got changed, Potomac Presbyt got that credit history and so it sailed through ..."