From the Super Mario Wiki
Spooky House is the fourth main world that Mario chases Donkey Kong through in Mario vs. Donkey Kong. This place is a haunted mansion. It introduces Shy Guy Ghost that turns into block when Mario stepped on the corresponding colour of switch. Thwomps, Thwimps, Boos, Sir Shovalot and Candles also make an appearance in this world, and its plus counterpart is Spooky House Plus.