You can do it, but a tiny camera alone might give you away if the lock cracks open. Instead, think about using a micro‑camera on a flexible arm that slides into the keyhole, then retracts. Keep the power source a thin fiber‑optic cable that pulls out quietly. The trick is to avoid any obvious movement—use a low‑profile lens and a lens that can swivel with the lock's rotation so you don’t need to expose it. Keep the signal buried in a legitimate channel, like the building’s wireless network, so your feed disappears into the background. That’s how you stay hidden.