Jack-o'-lantern with Fog (No Dry Ice)
Fog and Halloween go together. So what could be more appropriate and spooky than a jack-o'-lantern with fog curling out of its mouth and eyes. Now you could resort to 'fog juice' heated fog machines or dry ice, but I have always liked using ultrasonic humidifiers to produce fog. They don't have the hassles and hazards of procuring dry ice and the fog hangs low just like dry ice fog. Ultrasonic humidifiers* are relatively inexpensive with the least expensive starting around $30 on the internet and thrift store acquisitions setting you back far less. They also require little attention after set up allowing you to enjoy your Halloween festivities rather than attending to a fog machine or adding dry ice.
*An ultrasonic humidifier uses high frequency sound waves in the water to break the surface tension and produce extremely fine water droplets - fog. This type of humidifier is often referred to as cool mist or visible mist; however these terms are also sometime used to describe non-ultrasonic types also. Ultrasonic humidifiers do not use heaters and do not have paper filter media that evaporates the water. You want to make sure that the humidifier produces a visible 'fog' without the use of heat or filters; then you can be sure you have an ultrasonic humidifier. You can also identify an ultrasonic humidifier by the presence of the piezo disk located in the bottom of the water tray (see step 4).
You will need the following supplies and tools:
Jack-o'-lantern - You can carve your own or use a plastic one.
Ultrasonic Humidifier (As noted, a thrift store is a good option, but you might want to make sure it works before leaving the store)
Foam pipe insulating wrap - 'non-slit' type if available. (Other types of tubes will work, but this was least expensive option at <$2.)
PVC pipe fittings (see text)
Duct or Masking tape
Utensils to carve your Jack-o'-lantern