Aspects of the present disclosure are directed to increasing protection against electric shocks when a person is working on an electrical system. In some embodiments, the electrical system includes at least two different circuits and a safety module. An emergency signal input is provided on the safety module, and when an external emergency signal is received via the emergency signal input, the safety module shuts off a configured first circuit the associated switch and at least one further circuit via the associated switch if the safety module still receives the emergency signal at the emergency signal input after a predetermined period of time.