* On the overhead console: This is the most common location. Look for a small switch on the overhead console, near the rearview mirror or the map lights (if equipped). It might be a rocker switch or a small rotary dial.
* On the driver's side A-pillar: Less common, but some Rangers might have the interior light switch located on the A-pillar trim near the driver's side. This would be near the other switches and controls in that area.
If you can't find it in either of those locations, check your owner's manual. A picture would be very helpful!