Electrical timer modules that interact with one another so as to effect random operation of a plurality of electrical devices, creating the appearance that the devices are not operated automatically. The timer modules include circuitry that allows them to wake up from a sleep state or mode within a random time interval. Upon waking from the sleep state or mode, each modular timer initially senses for the presence of a transmitted signal. Upon receipt of a transmitted signal each module returns to its sleep state or mode. If no transmitted signal is received, the first timer module that wakes up transmits a signal to the other modules and activates an electrical device connected thereto.