Electroscope

Take your hot glue gun, plug it in, and turn it on high heat. The hot metal bit will be used to melt a hole in the center of your plastic lid. You can use a drill for this part, however, not everyone has access to those. Once the hot glue gun is hot enough, press it to the center of your plastic lid to create a hole. 

*Sometimes the plastic will only stretch and not break. This is fine, just use your scissors to cut the stretched part off to make the hole. 

Now take your copper wire, and create a small hook at one end. It doesn't need to be larger than a centimeter, but do make sure it is a little wide, about as wide as a pencil is thick. Once that side has a hook, put the copper wire through the hole of your plastic lid, hook side on the bottom. Temporarily place your lid on the jar to get the level of the hook right, it should be at least 3 inches from the bottom of your jar, and must not be touching the sides. Once you have your desired placement, use the hot glue to keep it in place, holding until the glue cools. The other side of the copper wire on the top of the lid needs to be coiled, which can happen any way you like. Some like a neat spiral, some a tangled ball. Do as you wish, but leave 1 inch of space between the lid and your wire antenna. (This is the part where pliers are optional)

Now take your aluminum foil and fold it in half. Cut out 2 "leaves" with your scissors. These can be oval, triangle, or rectangle, so long as they will not touch the sides or bottom of your jar when they are in. I have found ovals and rectangles work best. On each leaf, put a hole on one side of the shape (this should be lengthwise, as they need to hang on your hook.)

Take your jar lid off and hook each leaf through the hole. It is okay if the leaves touch eachother. Place your lid back on and secure it. 

Air up your balloon, rub it on a carpet or your head to create static electricity, and test your electroscope by bringing it close to the antenna of your new device. The leaves should spread apart from one another. This is the same way it works with ghosts, as they can change the electricity around the antenna and make the leaves split just like the balloon.

Have fun spirit chasing with this low tech device. Remember to be nice.