There are three instances I know of off the top of my head.
A "real" prophet arises that leads others to go serve some other god(s) (Deuteronomy 13)
I've never encountered one of these performing real miracles, but then I don't go carousing in places they might be, and I can't say much about them.
A presumptuous prophet who prophesies in the name of God (Deuteronomy 18:22 -- not commanded to be put to death here).
There are plenty of these around. Their embarrassment should be punishment enough, in my opinion.
A corrupt prophet, like Balaam, also emphasized in the NT.
The OT treats him as a real prophet, not a fraud. He wasn't executed but apparently killed for being in the wrong place at the wrong time. There are perhaps plenty of these to go around, but I would not consider a corrupt fraud to be a Balaam. Maybe in spirit, but a real, disobedient prophet can be in danger with God in other ways.
Then there are corrupt teachers who are complete frauds.
Should false teachers be considered prophets? I don't know, and I don't really care.
My personal opinion is that there is a kind of unwritten difference between someone with the gift of prophecy and the office of a prophet. Even though Paul instructs the church to desire prophecy, one perhaps should not seek the office, because, for one, the church is a very different context as compared to the ancient Hebrew nation that received these commands. Exalting one's self is not without consequences, which an aspiring prophet may come to learn quickly.
I don't really want to discourage folks who believe they have the gift of prophecy, but it should be obvious that the stakes, whether in the church or otherwise, are high with God. What purpose does it serve to occupy the office of prophet? It seems pointless to me, except unless to protect parishioners from potential consequences for not recognizing the reality of the body of Christ, etc., but then I wouldn't say the office itself is beneficial -- I think earthly authoritarianism is a hindrance.
Then there are those occasions where anyone, I don't care who you are, may feel compelled under threat of being punished yourself if you did not speak what you were given to. Anyone playing prophet who isn't really compelled in that way might not be acting out of the right motives.
In the church, the whole thing really ought to just take care of itself, in my opinion.