是at his home，例如：

1.The police found a quantity of drugs at his home.警察在他家发现了大量违禁品。

2.He tackled a masked intruder at his home.他在家里抓住了一个私自闯入的蒙面人。

3.He was putting up a new fence at his home.他正在为自己家搭建新的篱笆墙。

是at his home。因为在表达“在家”的意思时，用介词at。