What type of switch is this?
I was just ordering some of these for a CNC setup. Here's (a few of) Omron's offerings. They are quite cheap. 


Fancier ones have a roller at the end of the lever, but the curved "simulated roller" is good enough for many applications (and might be a bit more repeatable if that matters- which it doesn't typically for a limit switch). 



They are SPDT so they have both a N.O. and a N.C. contact, just ignore the one you don't need. 

For more space-constrained applications, there are many, many types of tiny SMT limit and detector switches used in things like optical drives- though most are normally open. Here is a photo of one (credit to Digikey): 



This one is only about 5mm square, not counting the plunger.