I'm trying to figure out regulatory requirements for residential electrical installations. Specifically, when is a licensed electrician required by code to perform an installation? Obviously you don't need one to install speaker wire. What about 120VAC line? Is there a voltage cut-off where low-voltage is less regulated than high voltage? If so, what is the cutoff? I should say that I'm only interested in installations up to 120VAC.
The reason for this question is that we are designing an electronic product to be installed in homes and would like to make installation require as little professional work as possible. Ideally this product could be installed by someone at the audio/video level of skill/licensing. We will run off a DC power (power supply would connect to 120VAC and likely be installed by a licensed electrician) but have a choice about what voltage to use. Higher voltage is better for electrical reasons but we don't want to trigger all kinds of complications with the installation.
I understand that codes vary by geography, and ideally the answer to this question would cover the differences in every region across the US but that's a long shot. If you only know your local code, then it is still helpful to me as long as you tell me your region.