You could certainly do the maggots appearing from, say, a cut. But as for them actually travelling to the cut, im not so sure. I take it you're after something that looks similar to the mummies on films like 'The Mummy' when the beetles are crawling in and out of the skeleton... only you want to do it with your skin?
Maggots get into cuts from flies laying eggs into flesh and them hatching and feeding off the flesh

(thats just gross!). So having them just crawl into the cut wouldnt be as realistic, unless you want to somehow find a way to atract flies and start laying eggs, and then for the eggs to hatch all in front of an audience.
Maybe instead of having the transposition, you could do something like slashing your wrist and reaching into the gash with maggots coming out of it, and you remove their signed card from your rotting arm.
I was born with Multiple Personality Disorder. Luckily, they are all me, they just dont always get along...