A screen door catch is the part of the latching mechanism that attaches to the door frame. When the door is closed, the striker on the door engages with the catch to latch the door. Over time the catch can become worn, bent or broken and will need to be replaced with a new one. A replacement catch is fairly inexpensive and can be purchased from most hardware or home improvement stores. It is installed in about 10 minutes.
Unscrew the screws that secure the old catch to the door frame using the proper type of screwdriver depending on the type of screws. Remove the old catch.
Hold the new catch on the door frame approximately where the old one was located. Close the door slowly and align the catch where it will engage with the striker on the door. This is accomplished more easily from the inside of the door.
Insert the screws into the screw holes of the catch and into the wood of the door frame. Ensure that you fasten the screws straight into the frame and not at an angle. Tighten the screws until they are snug, but do not over-drive them.