I think I know what you are refering to this and just a suggest but a door jamb switch may work for your useage but the curpit is the rating of jamb switch IIRC it will be about either 5 or 12 amps depending on what model you get.
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)
Square D has a class 9006 L100/300 series rated for 20 amp continuous (page 21-34, digest 175) but you are going to pay for it. Other manufacturers have similar but I don't have current catalogues. As far as size goes I would go for the small switch (less damage to the cabinet over time) to a relay, it may be about similar in bulk. I am glad we don't have that requirement.
Square D has a class 9006 L100/300 series rated for 20 amp continuous
I thought it was a normal thing for residential work, but the wholesalers haven't heard of such a thing, and I have to do two. At the first I used a limit switch and a 20 amp relay, because the wholesalers told me a 20 amp limit switch isn't available. Now I know better and I think the switch alone is a better option.