I used to have a pair of blue sided fairy wrasses who would always jump into the overflow. It got to the point I would just flood the overflow (I put valve on the drain pipe, so all I had to do was close the valve and turn off the sump return) and they'd just jump back into the tank on their own.
Lost both those particular fish in the same night when the canopy door wasn't shut properly. Both jumped. Of all the rotten luck..
Moral: make sure you have adequate coverings if you have fairy wrasses. It's really a question of when not if and it's just better if they can fall back into the water rather than something else.
