Lever Switch

Levers appear multiple times throughout the Mario series. They are often times used to trigger special events or occurrences when pulled, pushed, or simply hit.

Donkey Kong
In Donkey Kong for the Game Boy, levers are used to control conveyor belts, moving platforms and elevators. They can also be used to make bridges appear and disappear, as well as opening and closing gates. The player can pull levers by walking up to them and holding the B button while moving Mario with the D-Pad in the desired direction. In some boss levels, Donkey Kong Jr. will also operate levers to hinder Mario's progress.

Super Mario Galaxy
In Super Mario Galaxy, Mario can activate levers by spinning them. Levers can have a variety of different effects, obviously depending on their location in the level, etc. Their functions can range anywhere from turning on lights in dark areas to causing entire platforms to move forward or backward. They are very common in this game, and therefore appear in just about every galaxy.

Super Mario Galaxy 2
Levers in Super Mario Galaxy 2 serve exactly the same purpose as in its predecessor, the only difference being that Yoshi now has the ability to activate levers through the use of his extremely long tongue, as opposed to Mario just spinning them. In addition to this, a second player can also use the Co-Star Luma to spin levers and activate them as well, thereby eliminating the need for Mario to come in direct contact with the lever in order to activate it.