At a performance of WICKED, the bubble caught in Glinda's wig during the opening sequence and started to drag the actress across the stage. (I wish I could remember who it was; it was when Ana Gasteyer was playing Elphaba). The bubble stopped and one of the Ozians came forward to disentangle her. Then she turned and gave the bubble a very Glinda-ish withering stare, got a big laugh, and went on with the scene.