How To Make A Block Blink/Flash Like a Flashlight

In my game, you need to make it past guard towers that shine a light at you. And if you get hit by the light, it will restart the level. I want the block to flash like a light so that the player can move past when it is off. Does anyone know how to make the block flash and only make the game reset when the player gets hit by the light?

Seems like you have it working? I took a look, and I see flashing lights that reset the level when they touch you.

One tip to make your game better:

Instead of making a normal player movement you could try to make a grid-based movement.
You can see how to create one in Help>Examples