How?
Crowbar on the floor underneath where you want your grille
place wires on the floor. This is complicated. Stand on the tile you want the cables to lead into. Eg, clicking a tile to the west of you will lay cable in the floor pointing at you.
Connect the cables to the live wires by ripping up more floor until you find a live wire, then just stand and click on the tile with the live wire.
I need pictures, but cannot get any. somebody rip up some floor tiles and take and send me a screenshot
anywhere will do