Gear warning systems are great, but not absolute or infallible. My gear warning system is speaking aloud before every landing: "Wheels are down for landing on land", or "wheels are up for landing on water". Other than my voice, my RG has no aural warning system for the gear. Passengers think I'm a little off the first time, but they catch on quick, when I explain the outcome of landing in error on the water with the wheels down.
Even a working gear warning system can be tricked into not sounding an alarm. I found while flying the Navajo, it was content to be landed by carrying some power across the threshold. Then I realized that I was defeating the gear warning system, 'cause I was not actually retarding the throttles onto the idle stops and gear warning switches, until it was too late for a warning to be of any use. I changed my procedure after that, and closed the throttles on approach, after the gear was down, then used the desired power, after listening for the gear warning horn.
Yes, the flying club at which I earned my PPL had a Cessna Cardinal RG as the "advanced" plane in the fleet (and back in the day, it was $55 an hour wet). In a four month period, it was landed gear up twice. The second time, it did not return.
And, you'll find that most RG singles include in the emergency procedures for forced landing: "Select gear down", and "Master switch off". Depending upon how rushed you are, turning the master off shortly after selecting the gear down, may turn off the gear pump, leaving the gear part way down, and no gear warning horn, so everything will sound right, even though the wheels may not be down. About the only gear selection worse than "up" for a ground landing, is partly down.
In 37 years of flying, I have had 9 landing gear system failures, but I always knew I had the failure, and got them down for a no damage landing.