Halloween costume ideas for office?

Re: the tooth fairy. A big toothbrush with glitter could be your wand. You could buy/find a large brush that resembles a basic toothbrush in shape, then spray-paint it white (including the bristles),add some stripes on the side, cover it in glitter and hit with a coating of clear lacquer to finish it off. If the handle doesn't have a hole, drill one, and then curl a bunch of different colored ribbon and tie it to the end.