WASHINGTON—U.S. consumer confidence fell to a seven-month low in September as a relentless rise in COVID-19 cases deepened concerns about the economy’s near-term prospects, fitting in with expectations for a slowdown in growth in the third quarter. The survey from the Conference Board on Tuesday showed consumers less interested in buying a home and big-ticket items such as motor vehicles and major household appliances over the next six months. Consumers were also not as upbeat in their views of the labor market as in the prior month. Economic activity has cooled in recent months as the boost from pandemic relief money faded and infections flared up, driven by the highly contagious variant of the coronavirus. “But given that wave seems to be cresting, there’s hope confidence just hit its nadir,” said Robert Frick, corporate economist at Navy Federal Credit Union in Vienna, Virginia. “Assuming predictions of Delta dropping hold true, …