The vacancy in your heart doesn't connotes that nobody is seeking for the job of servicing your feelings, but because the employee must first have all the necessary credentials needed for the job.

A hole is a space where everything has been moved out so that opportunity has space to move in.

The first thing, of course, is to find a vacancy, a place where a teacher iswanted, and the second thing is to make the school officials believe you are just the person forthe position.