Sign up with an agency that provides extras for film and TV? I've heard the hours are long, jobs very irregular but pay is OK.
But in your 40s without drama school, experience and equity card I would guess properly paid speaking parts are, um, unlikely to say the least. My SiL is a trained and experienced actor (been in a lead role in the West End etc) now in her 40s and gets two or three proper acting jobs a year.
I agree that it would be an uphill struggle to find paid work acting on the stage; you will be competing against people of the same age who have a lot more experience.
Have you considered something like being a children's party entertainer? Then you would be putting on a show and getting paid for it, and you could start by using existing contacts/word of mouth. Probably still quite competitive, but less competitive than trying to be a stage actor.