An optical signaling device, in particular a signal pillar (1) of modular construction or similar with at least one first exchangeable light module (3) comprising at least one light element (10) is proposed for optical indication of one or more different operating states of a technical device (2) such as a machine, a plant, a vehicle or similar, wherein the first light module (3) comprises at least one first circuit board (11) oriented essentially in direction of a longitudinal axis (8) of the signaling device with the at least one first light element (10) and electrical components, wherein at least one contact (32) is provided between at least one first detachably contactable electrical contact surface (19) and a second electrical contact surface (18) of an adjacently arranged module (3, 4, 5, 6, 7) configured as a second light module (3) and/or as a holding module (5) and/or as a base module (6) for holding and connecting the signaling device at an operating position, wherein the adjacently arranged module (3, 4, 5, 6, 7) comprises at least one second circuit board (11) oriented essentially in direction of the longitudinal axis (8), which meets stringent requirements as regards the contacting between two adjacent modules and at the same time the constructional expenditure and/or realizes an improved energy/power supply of the modules. According to the invention this is achieved in that at least the two electrical contact surfaces (18, 19) of the contact (32), which can be detachably contacted with each other, are arranged between the first circuit board (11) and the second circuit board (11) in direction of the longitudinal axis (8).