>>513814210 (OP)
You're not the first one to notice this, OP. I've been seeing it for a couple of years now. Only when I'm near or inside a large city though. If you get as far away from cities as possible, the sky stops flickering.
At first I thought I was losing my mind, but a few other coworkers noticed it too. I'm pretty sure aliens or glowies are using cities as hubs for something but I have no idea what.