Switches, Fuses and Circuit Breakers

Switches, fuses or circuit breakers should be installed along the live wire. This is because the switch, fuse or circuit breaker would break the current flow before it reaches the electronic appliance.
If the switch, fuse or circuit breaker is installed along the neutral wire, the circuit before the electronic appliance would not be broken, so current flows until the end of the live wire. If someone accidentally touches the terminal end of the live wire, current will flow through his body; the switch, fuse or circuit breaker cannot protect the person from getting electrical shock.

If the fuse or switch is placed at the neutral wire, then it cannot break the circuit at the live wire and we can get electrical shocks if we touch the electrical appliance

If the fuse or switch is placed at the live wire, it can cut off the current flow before it reaches the appliance. This prevents us from getting electrical shocks when we touch the appliance since no current is flowing through it.