This error is easy to make, the pilots believe what they see rather than what their instruments are telling them.
For example about ten years ago I was taking a FAM (riding jumpseat) on an Air Carrier from ATL to DAY. As the pilots descended toward DAY they spotted MWO (Middletown Oh) and thought that they were seeing FFO (Wright Patterson AFB). After a few minutes they spot FFO but think that they are seeing DAY, they report the airport in sight and are cleared for the Visual Approach. As they turn final, and the FO gets ready to lower the gear, I tapped the captains shoulder and say, "You are on final for Wright Patterson AFB, Dayton is over at your 10 o clock." The captain thanked me and we stopped our descent and turned toward DAY.
Having also worked at FFO for several years, we saw various airlines mistakenly try to land at FFO at least a couple times a year.
Mike