A method of making an electrical device comprising the steps: (i) providing a layer of interlayer material, preferably a sheet of interlayer material, having a first major surface and a second opposing major surface; (ii) positioning at least a first electrically operable component on the first major surface of the layer of interlayer material, the first electrically operable component being mounted on a first circuit board; and (iii) providing a layer of adhesive material to cover at least a portion of the first major surface of the layer of interlayer material and at least a portion of the first electrically operable component and/or at least a portion of the first circuit board such that following step (iii) the first electrically operable component is fixed on the layer of interlayer material by at least a portion of the layer of adhesive material characterised in that before step (iii) a flex circuit is positioned on the layer of interlayer material or the first circuit board, the flex circuit comprising a substrate having a first major surface and an opposing second major surface, the first or second major surface of the substrate of the flex circuit comprising a first electrical connector region thereon in electrical communication with a second electrical connector region on the first or second major surface of the substrate of the flex circuit by means of an electrically conductive track; wherein the flex circuit is positioned such that the second electrical connector region on the substrate of the flex circuit is in electrical communication and preferably mechanical communication with a first electrical connector region on the first circuit board. (i) providing a layer of interlayer material, preferably a sheet of interlayer material, having a first major surface and a second opposing major surface; (ii) positioning at least a first electrically operable component on the first major surface of the layer of interlayer material, the first electrically operable component being mounted on a first circuit board; and (iii) providing a layer of adhesive material to cover at least a portion of the first major surface of the layer of interlayer material and at least a portion of the first electrically operable component and/or at least a portion of the first circuit board such that following step (iii) the first electrically operable component is fixed on the layer of interlayer material by at least a portion of the layer of adhesive material characterised in that before step (iii) a flex circuit is positioned on the layer of interlayer material or the first circuit board, the flex circuit comprising a substrate having a first major surface and an opposing second major surface, the first or second major surface of the substrate of the flex circuit comprising a first electrical connector region thereon in electrical communication with a second electrical connector region on the first or second major surface of the substrate of the flex circuit by means of an electrically conductive track; wherein the flex circuit is positioned such that the second electrical connector region on the substrate of the flex circuit is in electrical communication and preferably mechanical communication with a first electrical connector region on the first circuit board. characterised in that before step (iii) a flex circuit is positioned on the layer of interlayer material or the first circuit board, the flex circuit comprising a substrate having a first major surface and an opposing second major surface, the first or second major surface of the substrate of the flex circuit comprising a first electrical connector region thereon in electrical communication with a second electrical connector region on the first or second major surface of the substrate of the flex circuit by means of an electrically conductive track; wherein the flex circuit is positioned such that the second electrical connector region on the substrate of the flex circuit is in electrical communication and preferably mechanical communication with a first electrical connector region on the first circuit board.