Oooh, you can try what I’ve done before. Leave the front door open with the interior dimly lit and her hiding in a dark room beyond. When the kids come, she steps from the darkness into the dim light, and it’s a pretty good effect with a masked costume.
[Image description: a dimly lit red room, with a dark masked figure with horns standing in the doorway beside a table draped in black with a vase of dead flowers. An illusion of hands pressing through the wall is projected onto the wall beside the figure.]
My exact thoughts! Also the dual meaning of “swatted.”