In this paper, the reverse time migration (RTM) method is applied to the single-frequency reconstruction of embedded obstacles in a wall to perform an introductory study for in-wall imaging. The aim is to determine the geometrical properties of an object embedded in a wall by the use of an information function provided via the RTM method. The method is based on the computation of that information function separately at each point on a reconstruction domain. It is defined as the correlation levels between the incident fields emitted from sources and the back-propagation of the scattered field. The problem is taken from a broader perspective in order to show and confirm the effectiveness of the method. For this purpose, numerical experiments within a fundamental scenario are determined in a particular order to perform an essential Monte Carlo simulation. The paper uses a comparative study to make an objective evaluation of the achievement level of the method in in-wall imaging. The results reveal that the method is at the applicable level of achievement.