In this chapter, we present a model designed to predict the risk of contact-based infection among family members within the home. A simulation based on this model visualizes the process by which the virus spreads throughout the house when individuals return home from outside. Using data collected from a survey on residents’ behavior, we analyzed contact behavior after returning home and generated datasets, including behavior history, behavior probabilities, contact probabilities, and the frequency of visits to each room. Based on the collected data, we developed an artificial agent model. These agents simulate movement and contact behavior after returning home, allowing the virus that adheres to their hands and personal belongings while outside to spread to household objects. The results of the simulation experiment revealed significant virus adhesion around the entrance and kitchen areas. As a potential countermeasure, early handwashing was identified as an effective intervention.