Trouble with a job opportunity in Moonlight Falls, any ideas to fix this?

I don't know what level you r sim has reached in the career. Is this the ghost hunter career? That career has bugs. The only way I've ever been able t o get a sim to level 10 in that career was to put him into a different household and leave him to it. That seemed to do the trick as next time I checked on him he was at level 10.