I have seen things and people that are not present, not peripherally as you are describing but as full visual hallucinations. The most striking was when I was an undergraduate and saw a young man talking to the dorm proctor who resembled one of our international students, but with dark hair. I asked the student and he became quite excited, believing his brother had come to visit for Christmas. There had been, however, no one there. Other things I've seen have been much less realistic, but no less real. All of this was before I was medicated, so I can't speak to whether your experience is related to your medication or your illness.

People with bipolar disorder sometimes do see things, hear things, or even smell things that are not in our environment. In really simplified terms, what is happening is that the parts of the brain that are supposed to receive information from the environment are firing more or less on their own and creating images, sounds, or smells instead. The right medication is often helpful, so it's a good idea to talk to your p-doc. You said you're already on a pretty complex cocktail, so your doc may be able to rebalance the meds you're already taking to better deal with this issue.

The other possibility, which you alluded to, is that you're getting spooked because you're working alone late in an old building with lots of history and lots of nooks and crannies. Please don't take offense at this suggestion, but you may want to ask the minister -- depending on your church's traditions, etc -- to pray with you in your office, to anoint the door frame with oil or holy water, or to do any other ritual that would be appropriate for asking God's special presence and protection there. And the next time you see something that doesn't seem to really be there, sing your favorite church song really loud! That always helps me chase away the beejeebers.