Ok...... this is what I did with mine & it works well.

I have a manual override switch in the dash so I can switch the rear light on at will & at the back I put a 15 amp toggle switch in line with the Negative/ ground wire to the light itself so when out camping or wheeling I can switch it on & off from the back as long as the dash switch is on.

Most of the power draw is sucked up by the light itself so theirs not much load placed on the switch. I've run it this way for 2 years now & its never failed me yet.