Product review (5 stars): Exactly what it says it is
After some searching, I settled on this part being the problem with my Frigidaire washer/dryer combo.  Another retailer suggested (on their site) that I would need a wire harness and latch as well (much, much more expensive), but that's not the case with my unit.  I would suggest, however, to take the old part out first and compare with the photo.  That would pretty much instantly tell you--and its not like you'll be able to use your washer in the meantime, anyway.

Used this part to replace an issue where the washer wouldn't start.  I would get a slight buzz noise (partial door alarm, I guess), and the cycle would not engage.  Dropped in the part and all is working as usual.

Super easy to replace--there's even a 2 minute YouTube video out there that goes into good detail on how to do it.  Essentially all you need to do is remove a couple screws, a spring-loaded securing wire, and unplug 3 plugs.  Boom.