15.25x20" thin paper sign for series of 12 cereal box insert cards issued in Post cereals in 1948. Cards were issued one per box and each box had matching box back story panels. Sign shows example box back for "The Mummy's Secret" w/additional boxes shown, including "The Teeth Of Death." These cards were based on the "House Of Mystery" radio program, an old-fashioned storytelling session featuring Roger Elliot (played by John Griggs) who was a ghost-chaser and scientist of the supernatural whose experiences were supposed to prove that the paranormal was in fact false. All cards feature Elliot involved in the "Mystery" and end w/him figuring things out but leaving the "Solution" to be revealed by the matching card. Unused price circle at bottom right. Horizontal fold line at center w/.5" tear at center left. Some scattered margin/corner tip wear w/a few margin creases. Fine/VF overall. Very interesting item for non-sports and cereal premium collectors. Rare and first we've offered in our 50 years. From the archives of premium creators Sam & Gordon Gold and comes with LOA.