In terrain generation, Lighting glitch "strips" generate

I was out adventuring when I found these really weird light glitch patterns very annoying as they spawn mobs from them I don't know what causes them. I have only been able to see these 3 so far but there might be more. They just spawned and seem to be not connected as when I tried getting rid of them it proved to be difficult ( Only a few blocks would get updated at a time I gave up trying to remove them).