Applications must be received and approved before the event. It helps them to know what is expected of them. You will feel much better when they are conducting themselves according to a set of standards that make you feel more comfortable having others work in your home. Their Disabilities Support Services Office works with children with special needs, their families and child care providers. Their Disability Counselors can help you find a day care or after school program in your area.
Some local colleges have large pools of student volunteers for community service.
A medical student worked in our home this summer as part of a community service program. Try contacting the Community Service Organization on campus. Linens 'n Things sells a variety of solid colors and Walmart sells prints. The parking there is free, and it's not too far. It will at least get you coffee and a bagel at Au Bon Pain.