Pundits and scholars alike suspect that Facebook plays a role in not only exposing Americans to misinformation, but also encouraging them to seek out misinformation from other sources. Whether or not Facebook is responsible for stimulating misinformation search beyond the social networking site, however, is an open question. If Facebook encourages misinformation search behavior, we might expect search volume on other websites to simultaneously decrease when web traffic to Facebook is comparatively low. Here, we exploit a naturally-occurring and exogenous interruption to Facebook's service to study the site's impact on misinformation search. Difference-in-difference analyses reveal that minute-by-minute Google searches for pandemic misinformation (e.g., unproven COVID-19 remedies, vaccine conspiracy theories) tended to increase during the outage period, in comparison to a typical day (and vs. a placebo). These findings are less consistent with views that the site stimulates misinformation search, and more consistent with a steady and transferable demand for health misinformation. Our results showcase the importance of examining not only the supply side of misinformation, but also the demand side.