We present simple schematics for a three-terminal nanoelectromechanical switch using a vertical carbon nanotube tip and planar graphene. We investigated its operational dynamics via classical molecular dynamics simulations combined with classical electrostatic theory and found that the key operation of the proposed graphene-based nanoelectromechanical switch is based on the following two characteristics. First, it has a low mass density, large area, and a flexible deflection of the graphene, and second, the carbon nanotube tip is narrow and sharp. The electromechanical dynamics of the graphene switch are well-balanced by five forces, with a capacitive force between the bottom electrode and the graphene, the van der Waals force between the bottom electrode and the graphene, the capacitive force between the carbon nanotube tip and the graphene, the van der Waals force between the carbon nanotube tip electrode and the graphene, and the elastic force of the graphene. ACKNOWLEDGEMENTS : This research was partially supported by the MSIP (Ministry of Science, ICT and Future Planning), Korea, under the C-ITRC (Convergence Information Technology Research Center) (IITP-2015-H8601-15-1008) supervised by the IITP (Institute for Information & communications Technology Promotion), and partly supported by Basic Science Research Program through the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology (2015R1A1A1A05027643).