If you put the phone connector end of a phone charger in your mouth while the charger is plugged into a wall outlet, you will probably feel an acidic taste in your mouth. A USB charger produces 5V DC which is essentially harmless. It is quite common for people (myself, for instance) to test 9V batteries by touching the terminals with the tongue.
Note that if there was an electrical fault in the charger, shorting 120V live to the 5V output, you could be electrocuted. That’s very unlikely, though.
The conventional threshold for “dangerous” voltage is 50V. High-power connections are always dangerous, though. If you put car jumper cables in your mouth, the risk is not from electrocution but from burns, or from exploding the fillings in your teeth if they shorted out the wires.

Hmmm

Actually! Anything can happen especially when your village people are following you.

Yes..you are right. Any mains-powered device can kill anyone either through fault or damage.
Modern chargers do not use grounds and they use very tiny transformers for step down/rectifier/isolation; hence they can be particularly prone to leaking mains voltage/current to the user.

some people do that shit