Cut the end of the wooden strip (barrel) so it's slightly sloping (pic 1), and file a rounded notch in the end (pic 2). The side with the notch is the top of the gun.
Use a small file to roughen up the jaws of the clothes peg and file away the front edge to increase the angle so it will grab the cord better (pic 3). Hot-glue the peg to the wood on top and at the other end to the notch.
Cut a piece of the plastic tube 3 1/2 inches long and hot-glue it to the bottom of the barrel 1 1/2" back from the sloping end (pic 4). It must be exactly in line with the barrel.
Hot-glue the handle to the underside of the barrel, 15" back from the notch end (pic 5).
The SWAT Flykiller should now look like pic 6, and sliding the laser pointer into the tube should press the stud and turn it on.