i apologize if this has already been asked and answered, but I couldn't find it. I see many places in Survival where an area is illuminated, but there is no apparent light source. How do you do that?
Beacons provide a source of light through a certain amount of blocks. Even if they are not activated.
There are a couple glitches that do that if you place blocks down in a certain area that has already had a light source there.
This light glitch occurs when a light source is broken but not updated properly. You can fix it by replacing the old light source with another block (example: dirt) and it'll go away. * I visited the warp you mentioned and indeed that was the problem.