David Wulff said he was shopping at Arc's Value Village thrift store in Richfield when he stopped to read a framed letter to Santa Claus hanging on the store's wall, the St. Paul (Minn.) Pioneer Press reported Thursday.
Wulff said he was shocked to find the letter, which asked Santa for a "gas station," was signed "Harland Wulff, 33377 Belding Court, Wayne, Mich."
"I called my dad from the store, and I said, 'You're not going to believe what I just found -- a letter you wrote to Santa when you were 6 years old!'" Wulff said.
"I don't know whether my grandmother had stuck it inside something that I had donated -- or if I had sold something at a yard sale and someone had donated that item. There was stuff stuck in our family Bibles, but I didn't know there was stuff stuck anywhere else."
Wulff said he purchased the letter for $3.99 and mailed it to his father.
Harland Wulff, 69, said he received the toy gas station for Christmas in 1948.