Abstract: An occult device that includes an open-top hollow rectangular box, a light source, a first light transmitting sheet, a second light transmitting sheet, and an indicator. The open-top hollow rectangular box has a pair of long sides, a pair of short sides, a closed bottom, and an open top. The light source is disposed in the open-top hollow rectangular box. The first light transmitting sheet is disposed on the open top of the open-top hollow rectangular box, so that light from the light source can be transmitted therethrough. The second light transmitting sheet is disposed on the open top of the open-top hollow rectangular box and supported by the first light transmitting sheet, so that light from the light source can be transmitted therethrough. The first light transmitting sheet and the second light transmitting sheet close the open top of the open-top hollow rectangular box. And, the indicator is movable on the second light transmitting sheet by the hands of a user.