Short-term load forecasting (STLF) is indispensable for the efficient and cost-effective operation of power systems. The Kolmogorov-Arnold network (KAN), which is grounded in the Kolmogorov-Arnold representation theorem, exhibits superior interpretability and symbolic regression capabilities when juxtaposed with artificial neural networks (ANNs). It offers analytically expressible load formulas, making it a subject of recent research in short-term load forecasting. Nonetheless, as the depth of ANNs escalates, their predictive prowess frequently equals or even outstrips that of the KAN. To address this issue, this paper proposes a novel STLF method through the utilization and combination of Kolmogorov-Arnold Networks (KANs) and ANNs based on the idea of residual decomposition. KANs are utilized to uncover fundamental periodic and nonlinear patterns in the load, while the remaining residual component is fitted using ANNs. A hybrid model combining KANs and ANNs with residual connections is designed, explicitly satisfying load additivity. Additionally, regularization penalties are incorporated to ensure that the predictions made by KANs dominate, meeting the requirements of residual decomposition. Furthermore, a training method for the hybrid KAN-ANN model is proposed, which refines the analytical expressions obtained by KANs alone and provides more accurate forecast results. To validate the proposed method, we compared the forecasting performance of KANs, multi-layer perceptrons, and XGBoost using a public Switzerland dataset. Numerical results demonstrate that the proposed hybrid KAN-ANN method not only enhances the forecasting performance of the KAN-based method but also yields an analytical expression for STLF. Our code can be found in https://github.com/BozhenJIANG/KAN-ANN-for-STLF.