What's the name of this component (Mechanical Switch?)
It's a very cheap and unreliable version of what's commonly named microswitch. It's unreliable because the two flimsy parts which make up the contacts are unprotected and, well, flimsy. I would suggest you replace it with a real microswitch like  



The three solder contacts show that they're changeover contacts: one common, one normally open, and one normally closed.