I know that many ground crew are "afraid" of the Dash-8 propellers. Especially on the -100, where the distance between the GP receptacle and the propeller is very short.
The aircrew (or operator) generally wants the ground power plugged in before engine shut down. Normally both engines are shut down simultaneously. As the the propellers move through the Beta-range to the feathered position, the propellers give a short, positive thrust, which can cause the aircraft to "jump" forward, just as the ground crew have plugged in the GP.
Especially on icy tarmacs this is a problem, as the parking brakes don't prevent the aircraft from slipping forward.
The ground crew are risking their lives just to prevent the cabin from losing the interior lighting for a few seconds.
Nick.