The latest contribution to The Supernatural Writings of Stuart Palmer is an ostensibly non-fiction article, from the June 1929 issue of Ghost Stories.
In How a Spirit Corrected the Standard Dictionary, Palmer relates how the ghost of Henry Ward Beecher sends a message to his friend Isaac Funk, during a seance. Funk was co-founder of the publishing house Funk & Wagnalls, who produced a number of authoritative reference works, including the Funk & Wagnalls Dictionary.
According to the story, Funk and his colleagues inadvertently misplaced a valuable ancient coin, and made an error in verifying its authenticity, to boot. So Beecher had to send a message from the Beyond to fix the situation.
This is supposedly the incident that converted Isaac Funk to a believer in Spiritualism. He wrote about the events in his book The Widow's Mite and Other Psychic Phenomena (1904). I imagine that Palmer's account is based largely on Dr. Funk's book.
Personally, I prefer Palmer's short stories to his "true ghost experience" articles. But those interested in Forteana and similar subjects might find this an interesting and readable account of an allegedly real-life psychic phenomenon. And if you are interested in reading more, there's always Funk's own account, linked above--complete with attestations, possible explanations, and extended discussion.
I've also added publication information for two other pieces to the Stuart Palmer project page; unfortunately, I couldn't find the relevant magazine issues online.