I'm not an attorney, but from how I understand "wreck-less endangering", is if the round passes your property line. So if you shot in the air, it is possible, unless you have a huge area of land. This would be for your attorney and the state to prove. And keep in mind, everything you say can be documented.
What I was taught in my handgun class was the following example: You're clearing your gun and it goes off. Round goes out the window or threw the wall. It's WE. If you're pointing the gun at your floor and cops come and you can show them the round that went off, then not as bad. My instructor suggested to buy a ballistic pad and point the muzzle at that when "clearing" a gun. This way if it does go off, the pad will catch the round that you can show to the police.