The proliferation of cyber-physical systems is driving the growing need to establish links between these systems and virtual environments. Particularly in the smart grid, the high costs of some devices and the imminent need to prevent manipulation of these devices in production environments make mechanisms that allow the manipulation of these physical objects in virtual environments necessary; this has been called a digital twin (DT). Conversley, cyberattacks are growing in all cyber-physical systems and cybersecurity is essential to the critical infrastructure of the smart grid. This work shows a small implementation of a DT system for smart metering systems in a smart home environment for testing cybersecurity issues. The results show that the use of DTs is feasible in various contexts of the smart grid, particularly in cybersecurity testing.