A giggle switch is an illegal device that can be attached to a semi-automatic pistol, such as a Glock handgun, to convert it into a fully automatic machine gun. It is also known as a Glock switch or Glock auto-sear. The device is a small piece of metal that can be attached to the rear of the slide of a Glock handgun, and it allows the shooter to swap from semi-auto fire to full auto with a cross-bolt type switch. The term "giggle switch" is a slang term used to describe the device because it can make shooting a firearm so much fun that it can make people giggle. However, it is important to note that the use of giggle switches is illegal and can result in serious legal consequences.