by the longitudinal and transverse grid members 10 and 12 in substitution for one of the ceiling panels 14 the advertising display panel module 16 as can be best seen in fig1 3 in accordance with this embodiment of the invention is generally of a truncated pyramidal shape or construction having a base which is proportioned to be co extensive in area to the panel receiving areas defined by the longitudinal and transverse grid members 10 and 12 more particularly the advertising display module 16 has a horizontally extending peripheral rim 40 which is proportioned to seat on the horizontal leg member of the t shaped longitudinal and transverse grid members 10 and 12 to removably support the advertising display panel module 16 in a suspended position from the grid members 10 and 12 the advertising display module 16 has side walls 18 and 20 and end walls 22 and 24 integrally formed with the peripheral rim 40 and a bottom wall 26 in the illustrated embodiment the advertising display panel module 16 also has formed in its bottom wall 26 a truncated pyramidal shaped recessed cavity 28 having side walls 30 and 32 end walls 34 and 36 and a bottom wall 38 it may be noted that the side walls 18 and 20 and the end walls 22 and 24 preferably and advantageously are of a substantial width so.