Yes, and No...
You need to be applied in the very least at one of the schools, in order to apply for ET... And at least an ET to legaly work...
However, you may find a job where you might be hired as an ET and they may pay for, or at least a portion of it's cost through an association they may be a member of. Look at the list of schools and the associations sponsoring some of them, and track companies that belong to them, in fact contact those associasions themselves, they may be able to point you to someplace with a job to fill. My company is sponsoring 2 guys right now out of desparation, there may be other willing to do the same, if you can find them. Which may be hard to do until employers get really desparate. Expect desparation this summer... maybe... Too early to tell.
Or pay for all of it yourself, and find a job... It is your future and your Certification, they belong to you as your license to work. They do not belong to your employer.
Now you're right back where you started, with the chicken and the egg, finding a job in which experiance and training is nessesary, and needing experiance and training to get the job. If you are already in a program, that will be easier, and legal....
I'm just hoping you like the trade once you're in... There's a lot to know. I've been at it since 1990 and learn more all the time....