To find it, you'll need to:
1. Identify your engine: Look for an engine code (like a 2.3L, 3.0L, or 4.0L) on a sticker under the hood or in your owner's manual.
2. Consult a repair manual: A repair manual specific to your year and engine will show you a diagram of your engine and pinpoint the EGR sensor's location. Chilton's or Haynes manuals are readily available online and in auto parts stores.
3. Search online with your engine code: A Google search like "1996 Ford Ranger 4.0L EGR sensor location" (replace 4.0L with your engine size) will likely yield images and forum posts showing where it is on similar vehicles.
Without knowing your engine size, I can't give you a precise location. Keep in mind safety precautions when working under the hood of your vehicle. Disconnect the battery's negative terminal before starting any work.