Choose your bookshelf section where you want to install your secret compartment. Measure the height and width of the area. Cut a piece of plywood with these dimensions for use as front panel of your hidden compartment furniture. Measure and cut a piece of plywood to the same height, but subtract two inches (5 cm) width of the rear panel. Measure and cut two pieces with 1.5 inch (3.75 cm) in width and height of the area of your compartment. Measuring and cutting a bottom compartment for your, 1.5 inch (3.75 cm) wide and a length equal to the back piece least one inch (2.5 cm).
Position the side pieces on their long above the rear panel from corner to corner edges. Place the bottom piece between the sides of her long edge on the glue on the base. Let the glue dry for two hours. The front panel placed on the lateral and lower parts, allowing the protruding front one inch (2.5 cm) on each side hidden compartment furniture.
Place on the shelf compartment with the rear part facing the rear of the cabinet and the top side up. Enter the compartment to the bottom on the back. To retrieve the hidden compartment furniture, press any side from front to back edge.