Replacement Bulb - Inside Entry Steps

Inside the door to my MH, there are a couple of lights in the side of the stairwell to light the steps. One bulb is blown and I have never seen one like it. Don't have time to snap a pic, but it looks like the older cylindrical fuses - glass in the middle with silver metal on each end where it slides into the socket. It is about 1.5" long.

Can anyone tell me from this description if this is an automotive bulb perhaps? Not sure where to go looking for a replacement.