Recently, granulated metal nanostructures have gained considerable attention because of their potential for fabrication of novel nanoelectronic devices. In this work we present a numerical model capable of simulation of electron transport in granulated metal-dielectric nanostructures. The model is based on the direct Monte-Carlo simulation of single-electron hops between granules. Each simulation step includes calculating probabilities of all possible hops and choosing the one to occur by means of Monte-Carlo technique. The value of macroscopic electrical current is obtained by consecutive repeating of these steps many times and calculating the total charge transfer through a given cross-section. The model accounts for Coulomb interaction of charged granules in the presence of structural and energetic disorder. The developed model was utilized for the investigation of the field effect in thin granulated films. We have found that the film longitudinal conductivity could be effectively modulated by applying transversal electric field. It is shown as a result of numerical modeling that efficient modulation can be achieved if the proportion between charging energy of lone granule and energy of thermal fluctuations is not less than 10 and the amplitude of the random potential is low compared with the charging energy. We consider the metal granulated structure fabricated by laser electrodispersion technique which satisfies these requirements being a very promising candidate for current-switching device applications.