My 1950 ranch styled house has 3 wedges in my kitchen. They measure 5" across and 7"down, they are between my ceiling and wall. They seem to be solid and made up of plaster, they are on the perimeter of the kitchen 2 on one wall and 1 by itself. I would like to hang cabinets to the ceiling but they're in the way. Do they serve a purpose, if I take them down will my ceiling come crashing down?