Generally, yes. Neither PA law nor Federal law requires private employers to provide their employees with vacation time at all. All the law requires is that employers pay employees for time actually worked. So, in instances where an employer gives a salaried (exempt) employee vacation time and then closes the office, the employer can force the employee to use a vacation day. What an employer cannot do, however, is close the office and then refuse to pay a salaried (exempt) employee for that day on the basis that the employee has no more vacation left.
With respect to hourly (non-exempt) employees, PA and federal law do not require employers to pay those employee for hours that they would have worked, but for the office closure. But, an employer is still free to require hourly (non-exempt) employees to use a vacation day due to an office closure.
However, situations under the PA and federal wage laws are often extremely complex and fact-sensitive, so it is always a good idea to formally consult with an attorney about the specifics of your particular situation.