The relay screw terminal is used to connect appliances to the relay on the SNT kit PCB.
Find this relay screw terminal in your Kit.
Look at the end of this terminal, you will find three screw tumblers like this.
Left tumbler: Common —> To the power source
Centre: Normally Open —> To the electrical appliance (bulb)
Right: Normally Closed —> Leave this undisturbed
Use the electrical tester to loosen the screws on the terminal.
This is how the screw tumblers will look like when they are loosened.
Cut and strip a short length of one of the wires to your electrical device (light, fan, etc.). Plug the two ends into the terminal as shown.
Use the electrical tester and tighten the screws to secure the wires in place.
This is how the relay screw terminal will look like once the wires are secure.