An electrical circuit is comprised of a sheet of mycelium having a wiring pattern for an electrical circuit thereon. The sheet of mycelium is prepared from a solution of Potato Dextrose Broth and Potato Dextrose Agar that is inoculated with a macerated tissue culture including a filamentous fungi selected from the group consisting of Basidiomycota, Ascomycota and Zygomycota. A sheet of tissue that grows on the surface of the solution is extracted, plasticized and dried prior to being formed with the wiring pattern.