Switch Block (Super Mario 3D World)
From the Super Mario Wiki
Switch Blocks are a type of block similar in appearance to ! Blocks from previous games, appearing in Super Mario 3D World. Similar to the ON/OFF Switches in Super Mario World, Switch Blocks, when hit, usually change the direction of Switchboard tracks in stages they appear in. Switch Blocks appear in three stages: Switchboard Falls, Cosmic Cannon Cluster, and Honeycomb Starway. The one in Honeycomb Starway reveals a platform when hit.