Here's why:

* Insulators resist the flow of electricity. This is because their electrons are tightly bound to their atoms and don't easily move around.

* Plastic wrap is made from polymers, which are long chains of molecules with strong covalent bonds. These bonds hold the electrons tightly, making them poor conductors.

In contrast, conductors allow electricity to flow easily through them because their electrons are loosely bound and can move freely. Metals are good examples of conductors.