Abstract: A rotary cutter for cutting holes of various sizes in ceiling tile in connection with the installation of light fixtures. The cutter includes an enclosure which functions as a jig for receiving and accurately positioning tile members prior to the cutting operation. The lower portion of this enclosure functions as a waste receptacle following the cutting operation. A drive shaft turns a pair of arms bearing two cutter knives for rotation within the structure thus cutting holes in the ceiling tile. The cutting blades are biased upwards for returning to a non-cutting position upon completion of the cutting operation. The cutting knives are radially adjustable along the arm on which they are mounted. A conventional electric drill is mounted to the other end of the drive shaft for imparting rotary motion to the blade arm.