Electrically conducting composites are highly sought-after materials. Their capacity to withstand mechanical deformation while simultaneously offering facile charge transport recently opened numerous exploitation fields for them. In this contribution, composites were made from single-walled carbon nanotubes (SWCNTs) and ethyl cellulose (EC). Then, a straightforward process of doping involving water vapor was developed and tested over 30 days. The inclusion of water in the EC/SWCNT network resulted in a notable increase in the electrical conductivity from 250 ± 21 S/cm to 905 ± 34 S/cm. Interestingly, doping of the material experienced remarkable stability due to the favorable surface chemistry of the EC filler.