FWIW, I have a huge dresser that is in front of an outlet cover. You can't put the dresser flush against the outlet cover b/c of the plug. I had to rig up this contraption out of thick cardboard so my boys (about 12 months at the time) couldn't pull the wires down. Given what I saw last night, I have no doubt that my boys could have snapped the outlet cover after playing with it long enough; found the ricin and consumed it. Young kids are kind of relentless like that.Not saying it's going to happen...but it sets up perfectly.
I'm not sure a baby could open the capsule though. Holly would probably need to swallow the vial whole. I think everyone has assumed that Holly is the likely endgame for the ricin, but I'm beginning to doubt it. I think it could easily be used for Walt's last, most depraved act. Poisoning Hank before "disappearing" off to New Hampshire. It makes a certain amount of sense. It would be mostly untraceable, but apparent to Skyler. It's just the sort of thing that could motivate Skyler to take the kids where Walt would never see them again. He'd literally be poisoning his own family relationships (which is a recurring metaphor of the show).