Can some one cash cashier's check with my name on it ?

[Ben Kurt]

Because of the logistics I could not attend  most trustees auctions. I met a person there who said he can bid for me but I need to give my cashiers checks to him since trustees rep needs to verify before bidding.He  charges $1K. MY NAME is written at payable section on cashiers checks. So my question is, can he cash them or use them in any way other than paying real estate for me?