Measure the perimeter of the back of the TV stand. Mark the dimensions on a sheet of paper.
Purchase a piece of thin plywood or particle board big enough to cover the entire back of the unit. Purchase a package of wood nails long enough to penetrate the plywood or particle board and at least 3/4 inches into the wood on the back of the unit.
Measure and mark the perimeter to be cut on one side of the plywood or particle board.
Cut the plywood or particle board to the correct size with a circular saw.
Paint or stain the backing an appropriate color. Allow the paint or stain to fully dry.
Ask a helper to hold the backing up to the back of the TV stand. Hammer several nails through the backing and into the TV stand to secure the backing.