It has been some while since I posted this, and I haven't come closer to any results.
However, this is happening more often now, almost everytime I lay down and close my eyes. It never works with my eyes open tho.
But I can manage to let it go on for longer now, before I place a finger on my forehead to make it stop.

Would really like to find out what it is, if it is anything or just a nerve, or something I could develop.