A flat or substantially flat light-emitting and/or UV (ultraviolet)-emitting structure including first and second dielectric walls facing each other and defining an internal space containing a light source, first and second electrodes for the light source, which generate electric field lines with at least one component perpendicular to the first and second electrodes, the first electrode being supplied or capable of being supplied by a high-frequency electromagnetic signal f0, and as an outer cover for the first electrode, an electrical safety system that includes an electrical conductor separated from the first electrode by a dielectric, the protective conductor being connected or capable of being connected to an electrical power supply with a potential V and/or with a frequency f that are adjusted so that the peak value of external leakage current is equal to 2 mA or less if f is zero, or 0.7 mA or less if f is non-zero.