I know the #1 rule of migration is "Don't Migrate Crap", so if the question is crap but it has off-topic votes to migrate, I believe the proper action is:
1) Close for another reason if it makes sense
2) Edit/improve if it is on-topic elsewhere and can be made not crap
3) Leave open if on-topic here and can be made no crap
4) Vote to migrate if it is on-topic elsewhere and already not crap