If you reverse WEAPONS, you can split it into NOPE and SAW, two other horror movies

Some instruments that are only one letter apart
CLARINET and TRIANGLE
CAJÓN and BANJO
CLARION and OCARINA

Some cities and towns whose letters are all found in the states they're in
DORAL + fi = FLORIDA
FLORIN + caia = CALIFORNIA
RYE + nwok = NEW YORK