I have never heard of this, but apparently there is a plastic primer spray you can put down before you spray something (plastic) with paint so it sticks better. I found my can at Hobby Lobby.
I also found these chargers at Hobby Lobby on clearance for less than a dollar a piece.
I also snagged some plastic ornaments from the dollar sport at Target.
I marked off my area with painter's tape, and I sprayed. Next time, I'd get the brush on chalkboard paint, or cover the whole thing (not being sprayed with newspaper b/c I don't have accurate aim with spray paint).