Once the cake is cooled, use your hands or two forks and to crumble the cake into fine crumbs.
Add buttercream and mix with hands or fork until the buttercream is fully incorporated. You want the mixture to be just moist enough to roll into balls.
Using a small ice cream scoop, scoop out a small amount of mixture and roll between cupped hands until you reach the desired round shape.
Put balls on a plate and cover with plastic wrap. Place in refrigerator for at least 4 hours.
Place coating chocolates in a deep bowl so you will be able to submerge the entire ball in the chocolate. Melt chocolates.
Dip lollipop stick into chocolate and then into the middle of the ball. Let sit for 2 minutes.
Dip cake ball into the chocolate until it is completely covered. Hold it sideways over the bowl and rotate it and tap it so the excess chocolate comes off.
Push the lollipop stick into styrofoam block to dry.
Once the chocolate is dry, roll out fondant and cut out a circle with cookie cutter. Place the middle of the circle at the top of the cake pop. Pull down the sides so it covers the cake pop completely and looks like a ghost.
Use edible pen to make eyes and mouth.