You have to go to the Mexican embassy in Ghana which is paradoxically, located in Morocco. Yo can however complete the procedure by mail. On the related links section you can find the address and...
Here is a list of some things that you would need to get a fiance visa; if you are a law abiding citizen, if you have met your fiance in person, if you are both free to marry, can you support your...
You must be a law abiding American Citizen, be free to marry your fiance, and can support your fiance here in the United States. It is a lengthy process that can cost quite a bit of money.