I'm in the process of converting my O22 switch controllers to LEDs. A 11/16 black nylon hole plug snaps into the bulb opening, and I drill a hole in thecenter of each plug for the LED to pass through. The plugs are available for 70 cents each, but I need about 50. They are much cheaper wholesale. The minimum quantity is many times what I need. If enough others are considering a similar mod, a quantity purchase may make sense. The mod takes a little soldering, but is completely reversible. Please e-mail if interested. Thanks!