The answer is yes, and.
Many people who train as Laughter Professionals with a reputable organization add $1,000s to their annual income. Many of our students do so, helping clients of all ages to laugh to “live fully until they die” in various social, professional, and corporate settings. Note, however, that laughter is an extra revenue stream for them. It’s not their sole source of income.
Overall here is our default advice if you plan to do it on your own:
Don’t plan on quitting your full-time job just yet. Start somewhere and build from there. Gain some expertise both in facilitating laughter interventions AND as a public speaker.  You will typically only be able to start calling yourself a Laughter Professional after a minimum of 50 hours of hands-on practice.
Get comfortable selling. One way to learn that skill for free is to volunteer to fundraise a few hours per week for a local widow’s and children’s fund until you are not afraid of knocking on doors and being rejected anymore.
Educate yourself on how to best market and sell a service. Lots of good books have been written on that topic. Remember that there are no mistakes, only learning curves.