It is unlawful to advertise by displaying a sign or otherwise or hold himself or herself out to be a person engaged in the practice of fitting or selling hearing aids without having at the time of so doing a valid, unrevoked license or temporary license.
Source:
Section 2538.50, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=BPC§ionNum=2538.50..