RIP. At least some situations can be avoided though, like for instance 110V charging bricks used in a 220V outlet can go poof on their own, so thankfully your device is safe.
I'm sorry to strengthen your paranoia, with this response. I've put it in spoilers so you can opt to not read it.
Don't forget unloaded voltage could be like 20% too high, but the device is designed to tolerate the unloaded voltage, and it'll drop to the correct level during normal operation.
Also I have power bricks which RAISE the voltage when they are loaded...
Most likely the charger going boom wouldn't harm the device. In any decent charger, AC is separated from DC. But you never know, certain failures could lead to it putting out the incorrect voltage, or unstable power (which shouldn't harm a well designed device, but not all devices are well designed)