I have been wanting to do something like this for a while and on Black Friday Best Buy was selling a nice quad core phone for $9.99. I was able to snag a few of them to go inside some outlet mount control enclosures I planned to make. Some prototype pictures below.
The existing outlet switch is unneeded since the lights on the switch are all Insteon and need power at all times. I plan to wire a plug into the existing switch wiring to power a small wall wart for the phone PS. It should be a nice setup running Domo Pad. The whole assembly is fitted to snap and slide into place w/o the need for screws. I made it from PLA but ABS would be even better. If anyone wants the 3D files and exact phone model I'm using I'll be happy to provide. Thanks for looking - I guess I need to get hot on designing some control pages now.
I will update once it is installed and I hope everyone had a great holiday!