Can't really say where mine are wired into from memory as i never fitted them myself. but i did buy a switch for them to be turned on/off fitted on the handlebars, and when the key's switched off then everything is off.
I leave the spots on all the time as daylight running lights and they don't draw anywhere near the power that the headlights do so it's less strain on the battery for my bike as my commute isn't too far.
During the darker months i put all the lights on, the spots are aimed about 25-30ft downwards so not in anyone's eyes, they're just aiding my hunt for holes in the ground ahead of me plus the triangular shaped lighting pattern means even BMW drivers can see me through their sunglasses at night.