From the look in the picture, you have a 4-wire (White, Black, Red, and Green) cable. I can also see a White wire on the back side of the switch, but can't see what or how it's connected.
Is this 4 wire cable coming from your power source or is it one you used to connect from your switch to your motor ???
If used to connect switch to motor, will need to see how you connected wires to motor as well.It also looks like you have two unisulated wires connected to your switch. Unisulated wires are a bad idea as they can easily short out.
Just a guess, but it these wires look to be 12 or possibly even 10 gauge wires. While you can use them, 14 gauge would probably be a better option, if possible, as they will fit better inside the swith housing and be less likely to short out later on.