Would I have to build something that would plug into the Triggerlinc? I am still kind of confused on how it would work with only a triggerlinc, a metal box, and a button. Could you clarify for me?
Assuming that your button has 2 wires coming out of it, you can connect the button directly to the TriggerLinc. Inside the removable plastic case of the TriggerLinc, there are 2 bare wire "dry contact" ports. You'd push opposite ends of the stripped wires from your switch into the holes and tighten the screws to keep the wires from coming out. This dry contact port on the TriggerLinc can be used instead of the included magnet to trigger an ON or OFF INSTEON message. Press the button -> the circuit is closed -> TriggerLinc sends an ON message. Release the button -> circuit is open -> TriggerLinc sends an OFF message.
So, no, you wouldn't really have to build anything to plug into the TriggerLinc. Just connect the wires and put the TriggerLinc's plastic cover back on. If the button is big enough (and you can take it apart), you might be able to fit the TriggerLinc inside it, making it so you could put the button anywhere.
Alternatively, you might consider the RemoteLinc 2 wireless INSTEON switch (http://www.smarthome.com/2444A3WH/RemoteLinc-2-INSTEON-Wireless-Switch/p.aspx
). It may end up costing the same as a big button, wires, and a TriggerLinc anyway.