Is it possible for a Caribbean island to host a fifa football worldcup for example Jamaica?

Possible, but extremely unlikely. First the island would have to have all of the necessary stadia and facilities to prepare for the World Cup and they would have to have their bid to host selected.

Since almost none of the countries in the Caribbean would be willing to put up such a large amount of money into the stadia and facilities, as well as the fact that there would be little to no overall monetary gain from hosting the World Cup, there is no plausible reason why any of the Caribbean countries would want to host a World Cup.