WHAT EXACTLY IS A GAG BOX? According to collectors, the whole idea is to entice you to open the box up--like a funny three-dimensional greeting card. When you open it, it's not at all what you expected--but a gag! Gag boxes became very popular during World War II and actually held priority with mail service during the War. When the Washington D.C. postal service office was asked why these risqué and funny gag boxes got to the troops when other things didn't, they answered, “We’ve had combat fatigue cases that never cracked a smile for weeks until somebody handed them a gag.” Ain’t that neat?