The growing number of Prague shops devoted to all things Halloween—from pumpkins to fright wigs—says that in the Czech Republic, the holiday is here to stay. And given that Halloween is essentially a mash-up of the Czech children’s celebration maškarní ples (masked ball) and the Velikonoce (Easter) ritual of going door-to-door in search of treats, that makes frighteningly good sense. Some tips and tricks for outfitting your home and your family for the festivities.