Bridges made of ghost blocks may prevent mobs from pathfinding across while still being visually appealing.

Placing ghost blocks over pits or lava can trick players into thinking they are walking on solid ground.

You can summon a falling_block entity that stays in place. Use the command: /summon falling_block ~ ~ ~ {Time:1b, NoGravity:1b, BlockState:{Name:"minecraft:stone"}} Note: To make them permanent, use a repeating command block to constantly reset the Time tag to 1 .

If you encounter unwanted ghost blocks or need to clean up your build: Advanced Redstone Tutorial: Ghost Blocks in Minecraft 1.8

Includes a dedicated "Ghost Block" item that mimics surrounding materials but can be walked through. Common Uses & Hazards

In survival mode, standing on scaffolding and rapidly right-clicking to place more downwards can occasionally leave a single floating scaffolding block that is visible to you but not to others, allowing you to "fly".

Whether you want to build secret passages or just experiment with game mechanics, there are several ways to intentionally create these "fake" blocks.

Be careful on multiplayer servers. Interacting with unintentional ghost blocks (like standing on air) can trigger anti-cheat systems, leading to false bans. How to Remove Ghost Blocks