Most wiretap laws would not apply to a video recording, particularly if there is no sound. But this would vary from state to state. I personally don't believe a hotel maid has a reasonable expectation to privacy while cleaning a hotel room.

However, insofar as whether or not the material could be used in court, the answer is yes so long as the person making the recording isn't involved in law enforcement. The rules against illegal gathering of evidence only apply to police and prosecutors. If a private individual illegally collects evidence prosecutors can nevertheless use it. They may also prosecute the person illegally collecting the evidence, though.