An article incorporating a light or sound source (14) has two or more switches (18, 24, 26) which must be closed for the source (14) to be actuated, the switches being arranged to be successively closed at different stages of the packing, unpacking and using procedures. A first switch (26) can be a pull tab arrangement, closed on packing or unpacking the article. A second switch (18) can be a light-sensitive switch. A third switch (24) can be a user-operated switch or a tilt switch etc.