Have You Ever Hidden Something Behind a Wall? [POLL]

A Seattle-area man found a never-used coupon book from the 1950s behind a wall. He was delighted to find it. It reminded of another Seattle man who found a illicit drug-using kit hidden from the 1970s. Not long ago a Pendleton bed & breakfast found a bottle of scotch behind a wall from the prohibition era! I have never been tempted to hide something behind a wall. Have you?