electric, A/C, or plumbring)
Test is not hard. But you plan to work under a supervisor for 3 to 5 years as "Xue Tu".
Other way may be quick, real estate, personal finance.
I have reviewed them 7 years ago. I was a Sr. IC design Engineer then. Now I hold three license now. (real estate broker, mortgage broker, general life insurance, and general P&C insurance agent (last two be treat one license.
It is easier than getting a Master degree in engineer.