put a thick layer of vaseline on it, if it is a worm or larvae, it will need to come out for air and you can pull it out with tweezers.
I don't know how well this would work for worms or larvae, but I must stress NEVER to do this to a tick. Smothering it or stressing it out in any other way will cause it to regurgitate, and in doing so will spread any disease it may be carrying (Lyme is a prime example). Only ever use tweezers or a tick remover like Ticked Off.
Sorry - but I thought this was an important point to make.