The fact of the matter is that I have been asked twice this season to read to classes and had a great time at both of them. Nothing nefarious at all. That whole thought stream destroys the idea for me. No matter how innocently I'd approach the task there will always be a ton of other who would think differently.
You may want to contact your local school system and see if they have a substitute teacher program. Qualifications will vary from system to system. Our school system requires at least two years of verifiable college level courses.
I have a masters in education plus a masters in business and was once a certified math and science teacher. I taught full time for a while but needed to devote time to care for my aged mother. I now work as a substitute teacher and take assignments from anywhere from one to 40 days. I have now done this fro the past 10 years and average about 140 days of a 185 day school year. I have a lot of flexibility over which days I work but the school system expects substitutes to work at least 60 days per year.
I retired from a manufacturing company in 2003 and also worked in banking and in local government. Over the years, I have met several former coworkers who now work as substitute teachers to augment their retirement income. They have various 4 year degrees but no one was ever a teacher.
Getting paid for simply reading may be difficult as this is typically a volunteer activity. Also, as a substitute teacher, you typically get 15-32 students at a time.
Don't try to be a substitute teacher unless you can manage a classroom full of kids. Don't ever be alone with a single student of the opposite sex. Never touch a student.
The best way to be successful is to be able to teach an interesting lesson. The regular teacher is responsible for planning and providing the lesson. You can get kids interested by working a few problems on the board or helping them get started on a writing assignment. They are responsible for their own work so you cannot do their work for them.
With your background, you may think about an assistant with the school shop classes.
Most larger schools offer Metal, Wood, Voc Ag, Voc Auto, and other programs.
Around here, there is a program where kids who are slight problems in school excessive absence, tardy, or minor offenses, that may get them expelled, have to sit in on a class during the time they would normally be just sitting at home, or maybe getting in more trouble.
They use semi-retired or retired people to head the class, not just retired teachers, and make sure the kids are awake, and doing something constructive during that time.
This was started by the schools and the courts as a way to make sure these kids used their time off wisely, and not as a reward, or a vacation.
It seems to work, and I hear the classes are getting smaller.
Our local grade school has volunteers from other organizations come once a week for a one on one tutoring program to benefit children that are way behind in their reading. You have to do it because you want to. Heck, even the federal government is against it, they have lowered the mileage deduction for non profit work all the way to 14 cents per mile. That is going to really hurt a lot of ministers.