ZOMBIEPOCALYPSE adventure. But taking the time to search that shelf or closet offers no guarantee that you will find anything useful, and careless ransacking carries a risk of attracting the eager undead to your location.
At heart, the rules for Scavenging are a simple die roll; like most rolls in the game, a result of 4, 5 or 6 indicate a success. Characters who spend more time on the search can increase the likelihood of their finding something useful; those who rush the attempt will make it easier for the zombies to hear them.
These rules are mainly intended to determine the likelihood that characters will find an item on a messy shelf during a rushed search, such as might occur while creeping through a ruined town or building. For more relaxed examinations, the GM should just allow the characters to find the goodies without necessitating a die roll. Nor are they really intended to determine whether there is actually anything on the shelf (or cabinet, or closet) to be found, although I suppose it could be used that way. Rather, the GM should have an idea about what is on the shelf before the players start rolling and the results just indicate whether or not they found anything.
Now that I think of it, perhaps one of these days I should create a random loot table for the GMs.