In the off position, the tab should be forced down with the key in, and the spring action of the buzzer switch kicks it up when the ignition switch key is turned to the on or start position. This allows the tab to be pushed up and allows you to seat the plastic block of the switch all the way in. I guess with the key out, it should be ok as well, I've just never installed them without the key in place. With the key in, and in the off position, that buzzer tab should be locked in the down position. Something tells me there's something amiss in that switch dealio.
OH!!! Wait, I think I see it. Your buzzer switch clip appears to be in upside down or something is catty wampus. The metal springy thing goes on the bottom to push the switch up and hold it in place....look closely. That spring bar looks like it is going across the top. Get that thing out of there and fix it right! 🙂