World 3-Ghost House (New Super Mario Bros. Wii)

 is the first Ghost House level in New Super Mario Bros. Wii. It is unlocked by completing World 3-2, marks the first appearances of Boos and Big Boos. It also introduces a new enemy, the Obake Stand. Completing this level is not required to advance in the game, but doing so unlocks a Red Toad House.

As in New Super Mario Bros., all four Ghost Houses in New Super Mario Bros. Wii contain Secret Exits; finding the one in this level unlocks a Warp Cannon which transports the players to World 6.

Layout
When the level starts, a door can be seen; however, if the players attempt to enter, Boos will laugh and the door will disappear, leaving a coin behind. Behind the starting point is a wall with a hidden area with the first Star Coin inside. The players should go up the staircase while some Obake Stands and confronting two Boos. At the end of the path is another fake door, but there is a hidden area in the wall containing the actual door leading to the next room. Once there, the players must climb up poles while avoiding Boos. At the end of this area is another Star Coin hidden below the door. The next chamber is similar to the first one, except that the hidden area behind the wall contains a coin block instead of a Star Coin, and a rope is extended on the ceiling. Mario should grab it and then fall onto one of the moving platforms leading to the exit (see below for an alternative route leading to the secret exit). Outside, the players must avoid a Boo guarding the Goal Pole.

Star Coins

 * Star Coin 1: At the start of the level, the first Star Coin is in a hidden area in the left wall.
 * Star Coin 2: The second Star Coin is in a hidden area in the wall to the left of the four parallel poles.
 * Star Coin 3: Mario and co. must follow the path leading to the secret exit. While on the descending platform, about halfway down on the right is a hidden area that contains the third Star Coin.

Secret Exit
Upon seeing the first yellow moving platform in the third room where the players are climbing across ropes on the ceiling (pictured), they should stop and wait until it moves away. The players should then fall, landing on a hidden platform with a door. When they enter they will find themselves on a platform slowly descending, with many Boos floating around. On the right side, about halfway down the shaft, is a Question Block containing a Super Star. The third Star Coin is also hidden nearby. A door at the bottom of the shaft leads outside, where a Boo guards the Red Flagpole. This exit unlocks, a Warp Cannon which will take the players directly to World 6.

Enemies

 * Boos
 * Obake Stands
 * Big Boos