If you’ve heard of the English writer and wit Dr. Samuel Johnson, it’s probably thanks to his dictionary. Johnson was essentially England’s Noah Webster; he spent more than a decade of his life compiling a monumental Dictionary of the English Language, published in 1757. Johnson’s Dictionary remained the standard, go-to dictionary of British English for the next 150 years until the very first volumes of the Oxford English Dictionary began to appear in the early 1900s.

As well as his work as a lexicographer, however, Johnson was also an author, diarist, critic, poet, playwright, and, for a brief time in 1762, at least, a paranormal investigator.

This particular story begins in the early 1760s when a young couple named William and Fanny Kent began renting a room from a local landlord named Richard Parsons on Cock Lane in central London. Soon after the Kent’s moved in, Richard’s daughter, Betty, reported hearing strange scratching and tapping sounds all around the house. After a time, she eventually claimed to have seen a ghost manifest itself in her bedroom.

Word of the supposed haunting quickly spread across the city, and it soon came to light that William Kent was not only a widower but that his new wife Fanny was his deceased wife’s sister, Elizabeth. Given the laws of the day, such an arrangement was not considered legal, and Richard became convinced that the ghost must be Elizabeth’s. As a result, Richard blamed William’s unlawful marriage for all of the strange occurrences in his home and evicted the Kent’s.

Soon afterward, the noises stopped—but when Fanny suddenly died just a few weeks later, Richard reported that they immediately resumed. Believing that it was her ghost who was now haunting his home, a series of seances were held at the Cock Lane house to get to the bottom of the mystery. Reportedly, it was through these spiritual meetings that the ghost was indeed revealed to be Fanny’s, and that William Kent had poisoned her.

By now, stories of the Cock Lane Ghost were the talk of London. With a potential murder charge now mooted, the authorities were forced to step in and a criminal investigation was launched. As part of the inquiry, a committee was established to examine the details of the case, and, as one of the foremost enlightened men of 18th-century England, Samuel Johnson was invited along to record their findings. On February 1, 1762, Johnson and his team held one final seance at the Cock Lane house and he reported that Richard’s daughter, Betty, became “disturbed by a spirit.”

“While they were enquiring and deliberating,” Johnson wrote of his team, “they were summoned into the girl’s chamber by some ladies who were near her bed, and who had heard knocks and scratches. When the gentlemen entered, the girl declared that she felt the spirit like a mouse upon her back.” When pressed further, however, Betty became uneasy, and the investigators grew suspicious. “Though the spirit was very solemnly required to manifest its existence by appearance,” Johnson later recalled, “no evidence of any preternatural power was exhibited.” He ultimately was led to believe that, “the child has some art of making or counterfeiting a particular noise, and that there is no agency of any higher cause.”

As it happens, he was right. The investigation eventually discovered that Richard had borrowed a considerable amount of money from William Kent, which he had no means or intention of ever paying back. The two men had ultimately fallen out, whereupon Richard had concocted the ghost story in an elaborate attempt to frame William for both of his wives’ deaths. The ghostly knocking sounds heard around the house had all been Betty’s; she had secreted a tiny wooden board into the hemline of her nightdress, which she could then use to tap or scratch on the walls or furniture when prompted by her father. Both the Parsons, along with one of their servants and a preacher who was also in on the scam, were eventually prosecuted, with Richard receiving a two-year prison sentence.

The Cock Lane haunting had been revealed to be a scam, and Samuel Johnson’s time as a ghost hunter was sadly over.