  We have performed $^{75}$As and $^{23}$Na nuclear magnetic resonance (NMR)
measurements on a single crystal of NaFe$_{0.9835}$Co$_{0.0165}$As and found
microscopic coexistence of superconductivity with a two-component spin density
wave (SDW). Using $^{23}$Na NMR we measured the spatial distribution of local
magnetic fields. The SDW was found to be incommensurate with a major component
having magnetic moment ($\sim0.2\,\mu_B$/Fe) and a smaller component with
magnetic moment ($\sim0.02\,\mu_B$/Fe). Spin lattice relaxation experiments
reveal that this coexistence occurs at a microscopic level.
