Also found a bra....
Two years ago on a Celebrity cruise, first night there, my husband pulled a bra out from between the mattress and headboard of the bed. I was so grossed out and he just laughed and laughed!!
As a side note, a few weeks ago in our hotel room there were all kinds of fast food containers behind a night stand! A complaint to the front desk was met with a great deal of concern. I hope they confronted the housekeeping staff on that one!