The air bag light has been going on and off for about a week

There's a diagnostic fault code stored in the Air Bag Computer. Have that code read by a mechanic with a scanner that can access that computer. It will direct you to the circuit that needs further diagnosis.

Your description is typical of a clock spring coming apart. It's a wound-up ribbon cable in a plastic housing under the steering wheel. As it continues to break apart, eventually the horn and cruise control will stop working too.