A glitch that makes a piston double sided. Update: The setup only requires one piston, a block on top of the piston with activated redstone dust, and a block behind the piston. Also, it works with both pistons and sticky pistons. Works in other gamemodes (other than spectator) as well. Link to video:

https://drive.google.com/file/d/1bDwXOq_XftQfWevYQKT0qJF39XDAK8e8/view?usp=sharing