True, but it seemed that OP was implying that he wasn’t sure he knew where every camera was. He clearly seemed to be concerned that there was a hidden camera in the clock. What do you suggest for that situation?
If I had real concerns that my own house was bugged with hidden cameras I would either contract with someone who specializes in handling that sort of thing or sell the house. If doing the latter, consider any applicable disclosure laws and what you do or do not know about the house.