Shelly 1 12v light switch

how would someone wire a Shelly1 that only has two wires coming to the 12v light switch?

This isn’t really an openHAB question…

However - in this state, you can’t. Well, not at this location, anyway.

You’ll need to find the permanent power source, and make sure the Shelly is located there and has permanent power. You can then utilise these two wires going to the switch to toggle the output state of the Shelly, and then send the output to the light.