Tape off about 1/2 inch on all sides of the canvas to create a border. Cut out three different size ghost shapes from cardboard: 2.25 inches wide, 1.75 inches wide, and 1.25 inches wide.
To begin, open up the can of spackling paste. Starting with the largest cardboard piece, dip it in the spackling and scoop up a small amount.
Press the cardboard down on the canvas about halfway down from the top. As you press the cardboard down, the spackling will ooze out around the cardboard creating a textured outline. Pull the cardboard down along the canvas to create a ghost shape.
Repeat this process, overlapping the ghosts you create. Switch between the different size cardboard pieces to create different size ghosts. You can refer to the original painting to get an idea of how the ghosts overlap. For the most part, you’ll want to fill in one horizontal layer of ghosts before moving down to the next layer. Make sure to vary where the tops of the ghosts hit and how big they are as you continue to add them. Keep creating more ghost shapes until you fill in the entire bottom half of the canvas. If any of the spackling ends up sticking up, you can use your finger to gently press it down. As soon as you have finished adding ghosts, slowly remove the masking tape while the spackling is still damp and pink.
Now you will need to set aside the project for 8-12 hours until the spackling is completely dry. It turns white as it dries so it’s easy to tell when it's dry.
Once the spackling is completely dry, use a paint pen to draw eyes on each ghost. If you don’t want to purchase a paint pen, you can use acrylic craft paint and a small paintbrush – either paint the eyes with the brush OR dip the end of the brush in the paint and use it as a stamp to add the eyes.