Move your bed away from the wall. Measure up the wall with your tape measure and make a pencil mark 2 inches higher than the height of your bed frame. Hold your level against the wall. Line up the top of the level with your pencil mark on the wall. Adjust the level so that the bubble rests between the marks on the tube.
Draw a line across the top of your level. Move the level 4 feet to the right and continue the line to make it 8 feet long. Rub your stud finder along the level line on your wall while holding the locating button. Make a pencil mark on the wall every time the indicator light on the stud finder comes on and every time it goes off.
Hold the board against the wall. Place the top edge of the wood against your level line. Run screws through the board and into the wall with the Phillips bit on your drill Place each screw between the marks on the wall that are 1 1/2 inches apart and signify stud placement. Install a screw 1 inch from the top edge of the board and 1 inch from the bottom edge of the board at each stud location. Slide your bed back into place.