The commissioner may, from time to time, make reasonable groupings into type, types or kinds of insurance that may be lawfully written in this state, for the purpose of prescribing reasonable written examinations for producer and solicitor licenses for each group respectively, and for the issuance of limited licenses. Any such licensed producer or solicitor who shall attempt to write any type of business or seek a brokerage commission on a type of business for which he is not properly licensed and authorized shall, after investigation of all circumstances and proper notice of hearing, be subject to hearing for revocation or suspension of the license.