I like the wet/dry shop vac idea. Some, like my Craftsman, take the black bag liners. You could put stuff in the bottom then add a liner and it would cover everything if they looked inside.
If you even have an upright vacuum that takes the removable/replaceable bags, you can unzip the outer bag area and place the gun behind the bag and zip it back up. Had a friend that used to do that with his cash.
As far as a nightstand/end table, I wouldn't place a gun in the drawer or behind the swing drawer. If someone breaks in, they will probably look in there and see it. If you can, find a nightstand/end table that isn't solid all the way to the floor and has feet that raises it from the floor. I would mount the gun under the bottom side. Use and old leather belt section and make a loop to hold the gun, almost like a holster. Make sure it is tight against the bottom and doesn't hang down where someone may see it dangling.
I have a sideboard/buffet in the dining room. The middle section has approximately a one foot clearance where it doesn't go all the way to the floor. I mounted the cheap holster that came with my XD45 under that area and I keep my XD there. I can reach under there and draw the gun out of the holster. They can open all the drawers and swing out doors and they will never see a gun, just china and placemats and such.