This mysterious light appears on railroad tracks outside of the small town of Gurdon, Arkansas. Hundreds of people have seen the light since the early 1900s. It is described as white, blue, or orange/yellow and bobs back and forth. The light moves along the tracks for about 50 yards before it disappears. This motion is consistent with other ghost lights, and so is local legend, which attributes the light to a ghostly railroad worker searching for his head. Apparently there was a real murder at one time along the tracks, so perhaps the light really is ghostly in origin.
This page (http://www.ghosts.org/ghostlights/gurdon.html) last updated April 23, 2006.