Ow do i get to faraway island in emerald with mystery gift?

i read that WITHOUT a event or game shark you can get mew with the mystery gift in emerald and i read that if your lucky and you open the mystery gift it will say wonder gift and you will get the old sea chart and i also heard that there is a old man in pacilfdog town that looks out for faraway island and if your lucky he will spot it then you can go there is that true and how do i use the mystery gift to get the wonder gift