Wibbly lever

The wibbly lever was a part of the Doctor's TARDIS console. The lever had at least two functions: opening and closing doors (GAME: TARDIS) and controlling implosions used to revert paradoxes in which the TARDIS had materialised within itself. (TV: Time)

The one in the previous control room, which was set ablaze by the Tenth Doctor's fiery regeneration, malfunctioned, leaving the doors open; the newly regenerated Eleventh Doctor then nearly fell to his death. (TV: The Eleventh Hour)