29 CFR 785.23: Employees residing on employer's premises or working at home.

An employee who resides on his employer's premises on a permanent basis or for extended periods of time is not considered as working all the time he is on the premises. Ordinarily, he may engage in normal private pursuits and thus have enough time for eating, sleeping, entertaining, and other periods of complete freedom from all duties when he may leave the premises for purposes of his own. It is, of course, difficult to determine the exact hours worked under these circumstances and any reasonable agreement of the parties which takes into consideration all of the pertinent facts will be accepted. This rule would apply, for example, to the pumper of a stripper well who resides on the premises of his employer and also to a telephone operator who has the switchboard in her own home. (Skelly Oil Co. v. Jackson, 194 Okla. 183, 148 P. 2d 182 (Okla. Sup. Ct. 1944; Thompson v. Loring Oil Co., 50 F. Supp. 213 (W.D. La. 1943).)