In this paper, an automatic lighting controller designed and built using a wireless sensor network indoor positioning technology is described. This controller can autonomously track actors during a real-time theatrical performance. Kalman filter and 3D trilateration technologies were used with Cricket wireless sensors to implement this system. In addition, an entertainment industry standard protocol DMX-512 and an efficient calibration method were applied to realize remote computerized fixture control. As far as we know, this controller is the first application of wireless sensor networks in the theater arts area. A successful public performance concert at the University of Arizona validated the performance of the system