World 4-Ghost House is the Ghost House of World 4 in New Super Mario Bros. Wii.
In this level, at the start, the floor moves up or down when the player stands on it. At the left side of the beginning of the level, a Star can be found. Enemies found here include Boos and Scaredy Rats. The player must then hit a P Switch on the ceiling in a hidden alcove which requires standing on the floor which moves up. This enables access to the door leading to the next area. Through this door is a long area of stairways going up and done, where many clusters of Scaredy Rats run along. Near the beginning of the section, a hidden barrel can be found in a section of the ceiling. Past the area is the pole.
- Star Coin 1: The first Star Coin is hidden behind the platform to the right of the first Scaredy Rat. Mario and co. should stand on it to make it descend and reveal the Star Coin.
- Star Coin 2: The second Star Coin is in a hidden area, in the wall to the right of the stairs-like platforms with many Scaredy Rats. Mario and co. should run into the wall, jump up, and continue left to get the Star Coin.
- Star Coin 3: Mario and co. must follow the path to the secret exit. About halfway from the entrance to the exit of the secret room, the third Star Coin is floating to the high-left of a phony Warp Door. Mario and co. must get on the platform directly below it, wait for it to ascend high enough, then jump to the Star Coin, all while avoiding the nearby Boos. Mario and co. can also jump to the Star Coin from the aforementioned phony Warp Door.
- Before the door to the second area, there is a ? Block containing a coin (or a mushroom if the player is Small Mario). The player should stand on the platform below it to reveal a hidden door. They should then go to the door to the next area and continue to the hidden goal. This exit unlocks World 4- and a Yellow Toad House.