What happens when someone lets go of a button on an electric doorbell

An electric bell comprises of an electromagnet, a battery, spring and a clapper. When the switch is put on, the clapper becomes magnetic and hits the bell which produces the sound.

When the button of an electric bell is let go, the circuit breaks with a corresponding stop in the flow of current. The electromagnet also goes off with a corresponding direction change in the flow of current in the circuit.

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg