One backup light won't work on my honda oydssey?

The passenger's side backup light (reverse light) is not working. The driver's side is working and the fuse on the passenger's side on #10 is good. What is wrong?

Bad bulb? That would be the first thing to check. Try switching them. Next to look for would be problems with the wiring or the switch that is engaged by the shift lever. You'd probably need help with that from someone who knows what they're doing.

Oh my heavens. My husband connected the wrong wire.

Bad bulb, check it and replace as needed. Another option would be dirty contact on/in bulb socket.