Nanoscale electronics and photonics are among the most promising research areas providing functional nanocomponents for data transfer and signal processing. By adopting metal-based optical antennas as a disruptive technological vehicle, we demonstrate that an optical antenna coupled to a tunnel junction can be interfaced to create an electronically driven self-emitting unit. This nanoscale plasmonic transmitter operates by injecting electrons in a contacted tunneling antenna feedgap. Under certain operating conditions, we show that the device radiates a broadband light spectrum which can be related to a thermal like spectrum. We propose a model based upon the spontaneous emission of hot electrons that correctly reproduces the experimental findings. The electron-fed optical antennas described here are critical devices for interfacing electrons and photons, enabling thus the development of optical transceivers for on-chip broadcasting of information at the nanoscale. Based on the relaxation of hot carriers with life-times (ps) shorter than semiconductors, this technology could be a new paradigm for high frequency modulation.