Mists Over Carcassonne

Do I have to place a ghost, if I expand a mist bank with a tile, which shows only 1 ghost?

If you expand at least one mist bank when placing a tile (i.e. matched at least one side of the tile you just placed with mist already on the board), then you place one fewer ghost on the tile. If the tile only shows a single ghost, then you don’t need to place any ghosts.
Related Rule(s)