This command will add ghost blocks to your world, a ghost block is like a normal block but you can walk straight through it. The blocks will be put in your inventory in the form of spawn eggs when the machine is built. Some uses for these ghost blocks can be traps, secret enterances and much more. One lase thing i would like to mention is that the ghost blocks will be slightly out of place when you place them down but after about 2.5 seconds they will fall into place. It also needs to be pasted into a command block or it will not work.
I hope you enjoy this 8640 character long command! :D