While a Ghost minion could read: "When this card is discarded on your turn, play it as an extra minion instead of putting it into your discard pile."
I was thinking about that too. Cards that have extra abilities if discarded. I also predict something like, "Play this action on a base. Ongoing: Each time you discard a card from your hand you may destroy a minion with power 2 or less on this base."
These type of "when discarded" abilities would help make Ghost/Wizard a playable combo instead of having the Wizard draw power completely shut down the Ghost abilities (thereby making it an always-lose combo).