Jeep 2008 Wrangler - Manual (Page 97)

Also, the rear cargo lamp may be turned on by pressing
the lens. Press the lens again to turn it off. When a door is open and the interior lights are on,
rotating the dimmer control all the way down to the OFF
detent will cause all the interior lights to turn off. This is
also known as the
ЉPartyЉ mode because it allows the
doors to stay open for extended periods of time without
discharging the vehicle’s battery.
Cargo Lamp
Rear Cargo Lamp (Four-Door Models)
96 UNDERSTANDING THE FEATURES OF YOUR VEHICLE