This is the time to decide if you are going to add an on/off switch to your roaster. You can keep the cost down by eliminating the switch. However, when you are roasting coffee and the beans reach the perfect roast it will be more convenient to power off with a switch.
You will need to splice the power switch between the power cord and all other electronics. Make sure you give yourself enough wire to reach the mounting position of your switch.
You do not need to use heat shielded wire for the switch. You just need to mount it away from the heating chamber.
If mounted correctly you should be able to plug in the roaster without the elements getting warm or the motor turning. Flip the switch on and the motor will turn with the elements beginning to emit heat.