The tile.ghostLight.name is a technical block from Glow. It is used to expand the light source of the Glowstone Lamp. They appear and function exactly the same as air; they are not seen by the player in the world.
These blocks tick randomly to check if there is a lamp within range (see the Glowstone Lamp article for specifications on the range) in order for them to delete themselves from the world. Because they tick randomly, along with the Glowstone Lamp using a ticking tile entity, using this light source excessively may cause performance issues.