My wife has hidden a pocket knife under a floor standing ATM in the departure area at O'Hare pre-security and retrieved it when she got back, it wasn't discover

My wife has hidden a pocket knife under a floor standing ATM in the departure area at O'Hare pre-security and retrieved it when she got back, it wasn't discovered. Not recommended but there is a way to do this, "unofficially", success not guaranteed. Don't leave bomb-shaped packages.