What To Do If You Don't Have Neutrals
For all incandescent applications use the Insteon 2-Wire Dimmer. This switch does not require a neutral connection but note that it is for use with incandescent lighting:
Insteon Remote Control 2-Wire Dimmer Switch
Insteon 2-Wire Wiring
Get An Expert
When in doubt, hire a pro to find out if you have neutral wires in your switch box. If necessary they can "pull" neutral wires wherever you need them.
What About Using the Ground Wire If You Don't Have Neutrals?
While it is true that the ground wire and the neutral wires connect to the same place in your circuit panel, it is NOT acceptable by building and electrical codes to use the ground wire in this manner.