[hackerman12345]

There have definitely been recalls/warnings for firearms which have misfired without anyone's finger on the trigger.

https://www.cnn.com/interactive/2018/06/investigates/sig-sau...

[Sohcahtoa82]

Certainly. I recall seeing a video of a pump shotgun firing while the safety was on.

But as long as you always treat your firearms as loaded and never point it at something you're not willing to kill or destroy, you shouldn't have any "accidents".