Traveler's guide: How to spot hidden cameras and two‑way mirrors

When planning a domestic or international trip during the summer, we're often faced with deciding where to stay overnight. Options include hotels, apartments, or rental rooms. However, one must be aware that two-way mirrors might also be installed in these facilities in addition to hidden cameras. Learn how to spot them.

Numerous factors should be considered when selecting a hotel, apartment, or room to rent. Above all, safety should be the main priority. It has been found that owners of such facilities sometimes install various devices to observe guests.

Hidden cameras, which are often very small, are the most commonly used device. Yet, there are more covert methods of surveillance, such as the use of special mirrors known as two-way mirrors. Although it's rare to find such mirrors installed, the possibility of their presence in a rented room cannot be dismissed.

For many of us, spying is considered a serious invasion of privacy. Therefore, discovering a two-way mirror in a rented room can cause understandable concern. We can't be sure why it was installed, and we often suspect—rightly—that the installer had malicious intent, especially since there's no guarantee that we won’t be recorded or photographed.

Upon arriving at our accommodation, it is advisable to conduct a simple test using a mirror and a marker. If a marker is not at hand, we can use our fingernails. A video on TikTok demonstrates how to identify a two-way mirror using a marker. The link to the video is provided below.

Observing two lines on the mirror's surface (one drawn with the marker and its reflection) means we are looking at a traditional mirror. Seeing only one line might suggest the presence of a two-way mirror. This can also be tested with a fingernail.

The test involves placing your fingernail directly on the mirror's surface. If there's a "gap" between the fingernail and its reflection, it's likely a standard mirror. You may have encountered a two-way mirror if there's no "gap," meaning you seem to touch your reflection directly. However, remember that the perception of the image in the mirror can be affected by several factors, including lighting and the mirror’s material.

Another method to determine the type of mirror is to use a light source, such as a mobile phone flashlight. By turning off the lights in the room and bringing the flashlight close to the mirror, if you can see the space on the other side, it's a two-way mirror.