Cut a piece of 1-inch thick plywood into two equal pieces -- one piece to form the wall cleat and one piece for the nightstand cleat. Each cleat should be approximately 3 inches wide and 18 5/8 inches long, which is 1 inch less than the width of the nightstand.
Set your saw at a 45-degree angle and rip a long bevel along one long edge of each cleat.
Locate at least two studs on the wall where you are mounting the nightstand -- these are the ideal spots to mount the wall cleat since studs can handle more weight than drywall can. The easiest way to find the studs is with a stud finder, which beeps or flashes when it is near a stud. If you don't have a stud finder, use a hammer to lightly tap on the wall; the wall will have a solid sound when you tap at or near the stud.
Mark the wall where the top of the nightstand will rest. Place the wall cleat approximately 2 1/2 inches below that line.
Level the wall cleat to make sure the MALM nightstand will hang evenly and screw the cleat into the wall in each stud area, driving two 3-inch, No. 10 screws through the wall cleat and into the wall.
Place the nightstand against the wall, holding it in the spot that you want it hung. Place the other cleat behind the nightstand with the bevel facing the back of the nightstand so that it is resting on the cleat already installed on the wall. Mark the cleat in the place where it intersects with the nightstand.
Rip the cleat at your pencil line so that the top of the cleat will be flush with the top of the nightstand once it is installed. Hold the cleat with the beveled edge facing down and toward the back of the nightstand and with the top of the cleat flush with the top of the nightstand.
Screw the cleat onto the back of the nightstand. Use two 3-inch, No. 10 screws -- one near each end of the cleat for maximum sturdiness.
Lift the nightstand and slide it down onto the cleat. Once the cleats are interlocked, they will firmly secure the nightstand to the wall.