The prince invited my wife and I to dinner that night.
"Incorrect" and "hypercorrection" seem to me to amount to the same thing.
I was always taught to say (someone) and I for politeness (or so I thought, so it shoud be correct.
Should read as "The prince invited my wife and me to dinner that night." Remove the wife to see why..."The prince invited I to dinner" is incorrect.
In fact, it's incorrect, because "I" is the object of the sentence. However, this one is correct : "My wife and I were invited..."
how do people actually get this wrong? simply subtract the first object and "invited I" is obviously wrong. has an exception to the rule been taught re this? (i.e. what Jsmiley said)
Yes, it is incorrect. In fact, this kind of mistake (not only this) is referred to as hypercorrection.