An electronic device may have electrical components such as input-output devices. An electrical component may be mounted on a flexible printed circuit. The flexible printed circuit may have a bend that forms a flexible printed circuit spring to bias the electrical component in a desired direction. The electronic device may have a display with a display cover layer. In an inactive display area, opaque masking material may be formed on the display cover layer. A light window may be formed in the opaque masking layer. The flexible printed circuit spring may bias the electrical component against the display cover layer in alignment with the light window. An air gap under the electrical component may separate the component from a planar portion of the flexible printed circuit that is overlapped by the electrical component. The electrical component may be a camera, a light sensor, or other device.