An electronic switch for controlling a device (170) by switching a function of the device at least in dependency on a sleep stage of a human, the switch comprising an EEG data interface configured to receive brain activity data from an EEG sensor (120) configured to monitor electrical activity of the brain of the human during a training phase, an EEG sleep classifier (125) configured to classify sleep stages of the human from the received brain activity data, a body data interface configured to receive body activity data from an alternative sensor (30) configured to monitor a bodily function of the human both during the training phase and during a subsequent usage phase, the alternative sensor being different from the EEG sensor, an alternative sleep classifier (135) and a machine learning system (140), the machine learning system being configured to train the alternative sleep classifier (135) to classify a sleep stage of the human from the received body activity data, the learning system using sleep stages classified by the EEG sleep classifier (125) and concurrent body activity data received from the alternative sensor as training data, wherein in the usage phase the device (170) is controlled in dependency on sleep stages of the human classified by the alternative sleep classifier (135), and control logic (150) configured to at least determine that the classified sleep stage is one of a set of particular sleep stages and to switch a function of the device at least in dependency on said determination.
