Broken neon lights can be disposed of like any other broken glass. Please take caution and be careful to not touch or handle broken glass pieces. Due to the nature of thin glass, if your neon light breaks it will break into tiny pieces of glass. Using a broom to sweep the broken glass is the preferred method.
Once a neon light breaks or cracks, the neon gas immediately escapes and there is no gas remaining. Please dispose of the remaining pieces as there is no way to repair broken/cracked glass once the gas escapes. For more information on how neon lights are made, see our article on Real Neon.