I was trained in Electrical and data engineering 1980. Left the trade in 1989 and bummed around in IT making money, started a few businesses and made money, lost everything in 2008 (Thank you w/bankers) and eventually decided to get back into Electrical and Data engineering last year. One of the easiest options open to me (I thought) was a DEI (Domestic Electrical Installer) course for £4000. I had the money, I had the need, so I did it hoping it would open doors. It did not. I'm earning, but not going in the direction I expected.
If you respect yourself and wish to be respected within the industry I implore you NOT to go that route. Try, if you can to find a local college and do the FULL C&G 2330, 2392/2391 etc. At your age it is still worth doing and you will be around 35 years old when you're out the other end. THEN, you can command the respect that so many of us can no longer hope for. And you will know your trade and know your value.
I'm 56 and I took the easy route after so long out, but now I'm looking at different options. I'm lucky in a way because I have the finances to swap and change a few things like starting my own company (I already have) or buying a franchise perhaps. But making the right choice from the outset is of paramount importance. So read and digest the advice you get from these guys here. They know their stuff.
Other than that, I have nothing much to offer.
Best of luck to you.