See below

What you need for those are a mess of cheesecloth, fabric stiffener or
white glue, googly eyes (available in craft stores), balloons,
drinking glasses, and nylon thread or fishing line (optional). First,
blow up the balloons and set them in the drinking glasses; this will
provide a form for you to mold the ghosts around. Cut squares about
12-14″ of double layers of cheesecloth. Dilute the fabric stiffener
or white glue 1:1 with water, dip the cheesecloth squares in the glue
mixture and wring out the excess. Drape the cheesecloth on the
balloon in a ghostly shape. You can have the ghosts hemline trail
the table for a standup ghost, or you can have a sheer drop for a
flying ghost. Let dry overnight. When dry, remove the balloons, glue
on the googly eyes and attach nylon thread to the beads of any ghosts
you want to fly through the air. Hang the flying ghosts wherever
appropriate! The standup ghosts can stand on a table.