You say a hole. How big is this hole? You can try patching it with another piece of sheetrock or cut a new length of sheetrock to the proper measurments. A 1/2 inch strip can be cut and placed in the hole but the sheetrock may split when screwed into place. I'm assuming this is a rather long "hole". It's easier to just scrap the the one that was cut too short and cut a new piece to size.
