This is the last letter in John’s folder of Mary Hyre’s letters. She wrote it on March 24, 1968, and mailed it the next day, John’s birthday. She died on February 15, 1970. I assume they kept in touch by phone; they may have written other letters that John didn’t keep in this folder.
John wrote “MIB” on the envelope: the letter does describe a visit from a “strange visitor” with an intense interest in UFOs. There’s also a report on strange phone calls, and an update on Mothman witnesses Roger and Linda Scarberry.