The lights indicating four wheel drive is engaging continues to blink,

What is your question?

I took the car to a mechanic and when it was returned to me the four wheel engaging light was blinking. The mechanic said he put it in four wheel drive and then disengaged it but the light kept flashing. He attributed it to an electrical problem but this never existed until he drove it. I imagine a solenoid is stuck somewhere but can someone shed some light on what might be going on here.