There's an invader in Oak Park and he's wearing red, white and blue. And you've got to go find him.

Magic Tree Bookstore is inviting residents to find Waldo in Oak Park stores in honor of the 25th anniversary of the book series. Throughout the month of July, 20 participating businesses will have a 6-inch Waldo figure hiding somewhere in the store. After locating Waldo, the participant receives a card from that shop.

Once you've finished your hunt for Waldo return you cards to Magic Tree Bookstore, 141 N. Oak Park Ave. Collect eight cards and you receive a Waldo button. Collect 16 and you get a button and a chance to win the deluxe set of Waldo books.

There will be a Waldo grand celebration and prize drawing at Magic Tree Bookstore on July 31 at 7 p.m.

The participating businesses are:

Anasas, 109 N. Oak Park Ave. (closing soon)

Best Vacuum, 148 N. Oak Park Ave.

Bramble, 151 N Oak Park Ave.

Competitive Foot, 102 N. Marion St.

Croix, 131 N. Marion St.

Filoni, 131 N. Oak Park Ave.

Garland Flowers, 137 S. Oak Park Ave.

Geppetto's Toy Box, 730 Lake St.

Great Frame Up, 705 Lake St.

Green Home Experts, 811 South Blvd.

Irish Shop, 100 N. Oak Park Ave.

Knot Just Knits, 1107 Westgate St.

Magic Tree Bookstore, 141 N. Oak Park Ave.

Oak Park Records, 179 S. Oak Park Ave.

Olive & Well, 133 N. Oak Park Ave.

Picazzo Jewelry, 135 N. Oak Park Ave.

Pumpkin Moon, 1028 North Blvd.

Scratch N Sniff, 120 N. Marion St.

Shirtworks, 127 N. Marion St.

Sugarcup Trading Company, 110 N. Marion St.

Send photos of located Waldos to meg@oakpark.com.