Is expiation for an oath obligatory upon a wife if she says to her husband, "By Allah Almighty," meaning that he has tired her out by spending too much time on the computer? And is it permissible to give the value of the expiation for an oath to a charitable organization? And are sanitation workers considered among the needy?

There is no expiation incumbent upon the swearer for an oath concerning the past, and such an oath is not considered binding according to the most preponderant opinion. The ruling on an oath is based on the intention of the swearer. If he intended by his oath something that it could plausibly mean, then his oath is directed towards that meaning. Custom determines what is meant by the word "family/people" (الأهل) in an oath.