World 4-Ghost House (New Super Mario Bros. Wii)
From the Super Mario Wiki
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 Super 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. Past the area is the flagpole.