Divide the board into two by drawing a line. Write HAPPY HALLOWEEN at the right side and TRICK OR TREAT at the left side. Prepare a set of letters for the same words in two different colors (orange and black) and attach magnets at the back of each letter. Hide the letters in random around the room and group the class into two (2) teams. Assign each team a banner HAPPY HALLOWEEN (orange team) vs. TRICK OR TREAT (black) team. Say; "Go!" players start to find letters and form the words of their banner. If a player is on "orange" team and sees a letter for the "black" team he/she just leave it alone. The first team to complete their banner wins.
Note: To make the game more challenging players are instructed to follow the sequence of the letters on the banner.