Haunter evolves by trading, so in order to get it to evolve, you would have to either cheat, or use an emulator that also emulates trading. While there was one that claimed to do that a few years back, it was nearly impossible to get it to work properly. At the moment, I have not heard of any other releases that support multiple gameboy connectivity.
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In Shiny Gold which is a ROM hack of fire red. In SHINY gold version haunter evolves via lvl up the official Pokemon Community thread indicates so (http://www.pokecommunity.com/showthread.php?t=74447) in the Q&A near the bottom Zel did not specify at which level though.
Redownload the ROM, as it may be a bad one.
no in pokemon gold
the oval stone evolves hapinee give it to it (dont use it on it) and level up a few times
Why are you even playing heart gold? if you are then it must be the illegal ROM or something.