cargo light fuse in 2001 silverado

i have an 2001 silverado extended cab z71. does anyone know what fuse is the cargo light? not the cab brake light, but the white light that is on each side of the brake light (same light but different controls). the cargo light is turned on by the button on the dash that says CARGO LIGHT, but i can't figure out which fuse its on because i would like to add on some lights to be used with that button too.