What is the name of the Cars short film in which Mater sees a ghostlight?

Mater and the Ghostlight is the Cars short film in which Mater sees a ghostlight.

The short follows Mater after the residents of Radiator Springs play a prank on him by telling him about the Ghostlight, a mysterious blue light said to haunt the area. The joke makes him unusually nervous during the night.

Mater and the Ghostlight was directed by John Lasseter and Dan Scanlon. It was released in 2006 as a short film connected with Cars and later appeared on home-video releases associated with the feature.

The story uses the American folklore idea of a wandering ghost light, but its Cars version is a playful explanation rather than a serious supernatural tale. The short is separate from the feature film's main plot and should not be confused with the later Mater's Tall Tales episodes.