We report a theoretical study suggesting a novel type of electronic switching effect, driven by the geometrical reconstruction of nanoscale graphene-based junctions. We considered junction structures that have alternative metastable configurations transformed by rotations of local carbon dimers. The use of external mechanical strain allows a control of the energy-barrier heights of the potential profiles and also changes the reaction character from endothermic to exothermic or vice versa. The reshaping of the atomic details of the junction encode binary electronic "on" or "off" states, with on/off transmission ratio that can reach up to 10(4)-10(5). Our results suggest the possibility to design modern logical switching devices or mechanophore sensors, monitored by mechanical strain and structural rearrangements.