CRYSTAL LAKE, Ill. (WXIN) — An Illinois family has made the fast-food find of a lifetime: a 1950s-era McDonald’s order inside the walls of their house.

Grace Jones said she and her husband were updating a bathroom in their Crystal Lake, Illinois, home when they found the food.

Her husband, Rob, was replacing an old toilet paper fixture, and when he pulled it out of the wall, he noticed a piece of bunched-up cloth sitting in the hole where the fixture had been.

“At this point, we’re both looking at each other wondering if we’d be calling the police because we just uncovered evidence from a crime scene!” said Grace.

The couple said they were “very relieved” when the mystery bundle was revealed to contain a bag from McDonald’s with two burger wrappers and an order of uneaten, perfectly preserved fries inside.

“How on Earth are these fries still in this bag and how are they preserved so well?!” Grace wrote to WXIN via a Facebook message.

Grace’s home was built in 1959, and her theory is that one of the builders had gotten lunch from a recently opened McDonald’s down the street and then put the leftovers in the wall.

“Not sure if it was as a joke or to hide it from his boss, but either way, we’re glad it happened!” she said.

To strengthen Grace’s theory, she said they did some research and found the type of McDonald’s logo that was on the wrappers was only in use from 1955 to 1961.

Grace said they’d be happy to sell their discovery at the right price, but they will probably keep it as a cool piece of local history.