Theres a huge area of my home map and others that have these ghost lights scattered around, even in water sometimes. Some i can get rid of by updating the light by adding a torch and breaking it but not all of them will go away when i do it. Some will go away if i place a block directly at the point of the "light source" and break it as well. The area affected looks like the area of light a torch or other source gives off, a few blocks wide each direction. Some are grouped in lines stretching a good distance.