1884: The Rude Men in Red
The following account was collected in 1887 by folklorist William Martin while he was on vacation in the Isle of Man (in the Irish sea near Great Britain and Ireland). Martin eventually included it in a series of articles talking about British 'goblins,' or mean-spirited fairies.
One evening in the summer months of 1884, Martin tells us, a mail-cart driver on the island was running his late night/early morning rounds collecting mailbags from surrounding districts to deliver to a central location by one-thirty AM... only this night, he didn't arrive until nearly five-thirty in the morning, and he was noticibly scared and agitated. When asked why he was late, he explained that when he was about six miles away he encountered a troop of fairies dressed in red and carrying lanterns. Said fairies stopped his horse, threw the mailbags into the road, and then danced around them "in the well-known manner usual with fairies." For hours the postman struggled to replace the mail on his cart, only to have each bag he replaced immediately thrown back into the road again. This behavior continued until daybreak, when the fairies finally departed... after which the mailman recovered the mailbags and arrived at his destination, hours late and in an unhappy state.
Martin doesn't tell us the name of this mailman, but does explain that in meeting him the mailman did not strike him as the sort of person who would "fall a victim to his own fertile imagination." The mailman was well known for his sobriety and honesty, and he was not drunk when he left to fetch the mail that night, nor was he when he returned... just very upset.
Martin published the account above initially in the Brighton Herald for December 31, 1887, then again in an 1902 article for Folk-Lore... this account above is taken from the Folk-Lore article. I'll see if I can track down the earlier newspaper printing, as it's closer to the date of supposed occurence and I'm curious if the details are different or not.