You are likely looking for a Minecraft Redstone showcase or map download (titled something like "Crime Better") featuring a Piston Trap mechanism designed by Lovely Craft . The notation "Paper" implies this trap was likely built or optimized for a server running the PaperMC software to ensure it works without lag or bugs.
: The initial release focused on basic piston mechanics and a "sticky piston" physics game. v0.2 Series lovely craft piston trap v01 crime better