Just that there are very common. These are the sort of thing that would be good for any of the above ideas.
http://au.farnell.com/honeywell-s-c/bz-2rw53-a2/microswitch-wire-hinge-lever/dp/1262131
http://au.farnell.com/honeywell-s-c/sl-b1/limit-switch-spdt/dp/1525113
The wire actuator is often good because you can band the wire to get the actuation point just right.
Rob