Here is a good discussion about hazard light switches. @zKars identified three versions, thanks for the pic.

My #957 car has the one on the left that reads flash ,and my #6521 car (7/70) has the double triangle one, although some have told me that one is not correct for a mid 1970 car.

FWIW, here what the 1970, 1971 & 1972 owners manuals show. We all know how accurate they are. Lol

Fom = From. Lol

Here's the switch from my 12/70 car #17486.