For a 3-way switch application, you should only need one Micro Switch. Here is some documentation about all of the supported wiring options:
http://aeotec.com/support/1219-micro-switch-wiring-schematics.html
However, I would expect to see 4 wires in a 3-way application… Hot, Neutral, Load, and Traveler
Can you also open up the electrical box where the light fixture is mounted and see what the colors of the wires in there are?
Edit: I’ll just add that wiring the micro switch in a 3-way application is pretty difficult, and may require some changes to the physical wiring in your house. But we’ll do our best to help ya out here!