Whisperward

This ward can be applied to a single item or closure (such as a book, door, or lid), or it can ward an area up to 60 feet in diameter. The caster can key it to an individual, alignment, or condition in much the same way as a magic mouth spell. If the ward is triggered, a faint whispering breeze alerts the caster, who must be within 1 mile per level of the caster to be alerted.

The material component is mistletoe.