Like Steven said, 7th card face up as a community card for all to use.
Just make it clear beforehand about the rule.
I was once invited to a home game (deal rotates around the table) where this happened in a 7-card stud hand, but there were no concrete rules. When it was time for 7th street I had a monster drawing hand, but when it was time for the 7th card there weren't enough cards left for all the players.....so the dealer then said no one would get any more cards.

Guess who had the winning hand? Yup, the guy dealing who already had a 'made' hand.....Pisssed me off, but I didn't press the issue too much since it was my first time at this game. I was invited back to the game another time.....I not-so-politely declined to go back.
BTW, the guy was a 'big shot' retired CEO from a local hospital....crooked b*stard.