In the Wizards of Waverly Place episode entitled "Alex's Choice", when Teresa Russo decides to let her kids study in the lair, she unlocks the lock. The camera stays on her for a while as she decided whether to lock them in the lair or not. She decides not to and puts the lock on the table. In the next several shots after Alex enters the kitchen to talk about her problems, you can clearly see the lock is on the door.