A retired Michigan auto worker looked at a Facebook message after midnight from a stranger: Did you lose your wallet years ago?

“If so,” the Minnesota man wrote, “I found it in” the “engine bay of a car.”

Richard Guilford couldn't believe what he was reading on his phone in June. A mystery that had lasted more than 10 years was finally, remarkably solved.

Indeed, Guilford's tri-fold leather wallet -- stuffed with $15, a driver's license, work ID, gift cards worth $275 and lottery tickets -- had turned up in an auto repair shop this summer in Lake Crystal, Minnesota.

The wallet was discovered by mechanic Chad Volk under the hood of a 2015 Ford Edge. It was sandwiched between the transmission and a box that holds the air filter.

“I went down to the postal service, and I sent it back to him. And it took two or three days when he got it back, and he was excited,” Volk said.

Turn back the calendar to 2014, just before Christmas. Guilford was working on that car at a Ford factory in Wayne, Michigan, just another in a long line of new vehicles that needed extra electrical work before being shipped to a dealer somewhere in the U.S.

By the end of his shift, Guilford realized that his wallet had fallen out of his shirt pocket at some point. He said he was certain he lost it in a car but figured it was on the floor of a Ford Flex, not an Edge, and certainly not in the engine.

Guilford said he searched 30 to 40 cars, and his co-workers looked at dozens more.

Now, it’s back.

“When you lose something, you never know what's going to come back to you,” he said.