Slide these thin stiff plastic shims against the beveled edge of the latch bolt to force the spring latch bolt back into the door lock. This material is tough enough to wedge into most door jambs several times. Thinner, longer, and more flexible than a credit card, each shim is 9" Long x 3-1/8" Wide x 1/64" Thick.
This pack of 5 pieces of plastic will open almost any spring latch bolt. NOTE: These will not work on functioning deadbolts or deadlatches. However, many deadlatches are not working properly because the dead latching finger is fully extended into the strike opening. You can try to pull the door closed tighter to force the finger into the strike opening before shimming.