Do you mean a trem that looks like a vintage part ... 1957/1961? ie. traditional bent steel saddles stamped Fender?
The Squier has 'modern' Fender string spacing at the bridge (2 1/16) as opposed to the vintage Fender spacing (2 3/16) so you want a 6 point Fender bridge with modern spacing... as commonly found on the MIM standard 2006-2018.
The only downside is since the block (stamped PW29 on the bottom if genuine) is full thickness for the MIM it'll stick out the back a fraction on the Squier since both Bullets and Affinities have thinner bodies by 3-4mm. You can either do what I did when I fitted one to my Affinity and have a shop mill those few mm off (and re-drill the holes for the springs ... you'll want them to mill the bottom to maintain a factory fit to the bridge plate) or just leave the trem cover off.
Worthwhile mod if you like the rest of the guitar. My Affinity has a great neck with excellent fret work so worth the small investment to uprate very much the worst quality part (along with the tuners). Drop in replacement if you can live without the trem cover or do what others have done and move the trem cover 'up' off the body those few mm required by sticking something around the outside of it's underside
Last edited: Jul 11, 2020