Wall-Mounted 120V Button Controller for Smartthings?

Ok that means north America power and ZWave frequency… Good.

So one option is a Cooper lighting scene controller:
http://www.cooperindustries.com/content/public/en/wiring_devices/products/lighting_controls/aspire_rf_wireless/aspire_rf_5_button_scene_control_keypad_rfwdc_rfwc5.html

You will need a custom DTH with this device:

And you will need a button controller smartapp to handle the commands if the endpoint devices are not ZWave…

I personally use mine as a wall mounted control to handle a bank of roller shades.