Screen flashes once, then turns on when the screen turns on?

I have a Samsung Galaxy tab a, and just recently, as in tonight, my tablet flickers one time, then turns on when I turn the screen on with the power button or the menu button.

It is a quick flash and then the screen turns on and works normally. Both the home and the power buttons have the flicker. The only thing that happened between me noticing and using it, is my boyfriend laid on the bed and the tablet was under him.

Thanks!