It seems like a real phenomena, I wonder it there's anywhere that gets strong enough earthquakes regularly enough where a camera could be setup? Chile maybe?
Also interesting is during this earthquake they were apparently filmed off the coast, which probably rules out the local electrical grids.
The one at Sakurajima is a bit different https://www.youtube.com/watch?v=cOzSSfYi2UA also doesnt seem like electrical problems, but looks a bit more "alien spotted in home video"-esque