NO! NO! NO!
Some states (a few) do require a special license to practice home inspection – CALIFORNIA DOES NOT. There is an organization called ASHI (American Society of Home Inspectors) to which many home inspectors are members but this is not a government agency and they do not police themselves. It is intended to promote higher standards for the inspection industry, consequently an inspector who is a member of ASHI should be better informed than one who is not. – but maybe not.
Inspectors today are getting sued left and right along with everybody else in real estate. It is becoming a deep pocket business, so expect the price of inspection to get higher and higher. When the price gets too high, the state may consider requiring an inspectors license. Remember to always obtain a copy of the inspectors report.