Not sure what you mean with "lemon circuit", but in an electrical circuit, the switch can be just about anywhere.
A switch is placed in an electrical circuit in order to place a gap when the switch is off, so the circuit is broken. When the switch is on, the circuit is complete and the electricity can flow round the circuit.
If the circuit is complete then it shouldn't matter where the switch is located. All a switch is specifically is a segment of the circuit that can be connected and disconected.
From the standpoint of basic functionality, you can put the switch anywhere. In a series circuit, there is only one path for current flow. If you open the switch, you interrupt that pathway and turn the circuit "off."There may be practical reasons to put the switch in one place or another, however. Sometimes it's put in a particular place in the circuit for manufacturing reasons. In other circuits, safety may dictate that you put the switch in a particular place: in a ground-referenced circuit for example, you may want to put the switch so that one side is at the ground point.
To install a 2 wire 3 way switch in a circuit, first turn off the power to the circuit. Then, connect the two wires from the switch to the two wires in the circuit. Make sure to follow the wiring diagram for the specific switch model. Finally, secure the switch in place and turn the power back on to test the switch.
To remove a light switch, first turn off the power to the switch at the circuit breaker. Use a screwdriver to remove the screws holding the switch plate in place. Next, unscrew the switch from the electrical box and disconnect the wires. Replace the switch with a new one if needed, then reattach the wires and screw the switch back into place. Finally, replace the switch plate and turn the power back on at the circuit breaker.
To install a dimmer in place of a light switch, first turn off the power to the switch at the circuit breaker. Remove the existing switch and disconnect the wires. Connect the dimmer's wires to the corresponding wires in the wall box, following the manufacturer's instructions. Secure the dimmer in place and restore power to the circuit. Test the dimmer to ensure it is working properly.
A switch makes a physical break in the electric circuit. With the circuit broken the electricity can not flow. When the switch is turned the other way the circuit is completed and the current/electricity can flow.
To replace a light switch, turn off the power to the switch at the circuit breaker, remove the cover plate and unscrew the switch from the wall. Disconnect the wires from the old switch and connect them to the new switch in the same way. Screw the new switch into place, replace the cover plate, and turn the power back on at the circuit breaker.
To wire a dimmer switch, first turn off the power to the circuit. Remove the existing switch and disconnect the wires. Connect the dimmer switch wires to the corresponding wires in the wall box, following the manufacturer's instructions. Secure the dimmer switch in place and restore power to the circuit to test the dimmer switch.
It is generally not recommended to use a 120v light switch in place of a 125v switch. The voltage rating of the switch should match the voltage of the circuit to prevent potential safety hazards such as overheating or electrical arcing. It's best to use a switch that matches the voltage of the circuit.
To replace a dimmer switch with a regular switch, you will need to turn off the power to the switch at the circuit breaker, remove the dimmer switch from the wall, disconnect the wires from the dimmer switch, connect the wires to the regular switch following the same configuration, and then secure the regular switch in place. Finally, turn the power back on at the circuit breaker to test the new switch.
The switch needs to be in the "on" position for the circuit to work, allowing the flow of electricity through the circuit. In the "off" position, the switch breaks the circuit, stopping the flow of electricity.