1974 gold duster and PBR

On my car. 76 duster 4sp the reverse lite switch is in the same circuit as the turn signals. The reverse switch shorted and blew the fuse. Just a little help to get you headed in the right direction to figure out why the fuse was bypassed in the first place.
Thanks. have the switch replaced hazards work fine now but the turn signals are very eratic and the fasten seat belt light flashes with them. worked fine before so I guess im looking for more damage. oh and I have brake lights now. lol