In a public vanilla survival server, whenever I will get rid of a structure with any kind of light built in a past version, the light remains. Only when I place blocks at the exact location of the light does it stop.

I don't know if this is some kind of bug that can't be fixed, as lighting errors have been around for a very long time.

I don't know if it's only on public servers, as that's only where I have seen this glitch happen in this way exactly, but if a light source is placed, in what I assume is a past version, then switching back to the current version causes the light to stay, even after the block is destroyed. (The only way to stop the source light is to place a block in its location.