Peeping Tom laws—also known as voyeurism laws or invasion of privacy laws—generally make it illegal and a criminal offense to peek into windows or doors on private property to view a person who is fully or partially naked for the purpose of sexual desire or gratification.

Peeping Tom laws vary from state to state and some states require that the victim not realize he or she was being viewed and that the victim had a reasonable expectation of privacy (was in a place where it was reasonable to expect privacy). And some states specifically address the use of unmanned aircraft (drones), cameras, video cameras, and binoculars in connection with such peeping. Some state statutes specifically prohibit peeking into bathrooms, dressing rooms, showers, and baths. And some states characterize this criminal offense as trespassing with the intent to peer or peep.

Peeping Tom laws are located in a state’s statutes—often in the penal or criminal code.

In Wisconsin, Peeping Tom laws are addressed under the state's invasion of privacy statutes. Wisconsin Statute § 942.08 makes it illegal to invade someone's privacy by looking into a dwelling or other enclosed space without the person's consent for the purpose of sexual arousal or gratification. This includes situations where the victim is fully or partially nude and has a reasonable expectation of privacy. The law also covers the use of devices like cameras and binoculars to commit such acts. Additionally, the statute prohibits the installation of devices for observing, photographing, or recording images or sounds in places where a person has a reasonable expectation of privacy, such as bathrooms, changing rooms, or bedrooms. Violation of these laws can result in criminal charges ranging from misdemeanors to felonies, depending on the circumstances and the presence of aggravating factors, such as prior convictions or the age of the victim.