This swallow has built a nest in my house for the third time. Is it okay in the middle of the door?

Very good. Swallows are very spiritual things. They are all looking for a warm, harmonious and happy family environment to nest and breed their next generation. There is also a swallow in my house. It comes to my house early every spring, for several years in a row. After giving birth to a few swallows, they will give their nests to their children to eat, and the big swallows will stay with them for the night. When all the swallows are fed, it will get cold. They flew to a warm place in the south for a while and came back the next spring. I heard that southerners eat swallow meat, but I don't think so. I suggest you protect our good friend, Swallow.