TMCC freq also used by what?

The Cab-1 to base frequency is 27.555MHz. This is assigned for remote control. Devices that could legally interfere are car alarms with pagers and older wireless keyboards and mice and perhaps a paging signal in a home intercom.

The base would have to be powered for interference to affect it.

You can read more here under Shared Radio Services. It's a little muddy about Part 15 devices and broadband over Power Line leakage.

Pagers can interfere also. (does any still use them?)

Could your 1 year old have been trying to learn Cab-1 remote operations after flipping the PowerHouse on? May be a little early, but kids now days pick up on the electronic stuff pretty quickly.

Only if he can reach a self that 6 foot in the air. 

I know a guy that still uses a pager.  He also still uses a slide rule...

But the car alarm thing is what I'll mark it up to.  The guy across the street has a car alarm that, IMHO, is messed up.  It goes off every time he starts the car up.  He's also the kind of guy that fixes cars in his driveway, so there is always like a dozen cars around.  Makes it hard for company to find a place to park when they come to visit me.  More so now that he's lost the parking spot of the empty house's driveway next door now that it's been bought.  And there is always an alarm going off with him standing out there trying to shut it off.

It could be the pager letting the network know it's still alive. Kind of like when you have your cell phone near the computer. You can hear the signal in the speakers.

it could also be CB guys on channels they shouldn't be on, with an occasional mike key  that gets you. Anyone around have big clothesline looking antennas or large antennas?

The FCC used to police that stuff, but not much anymore.

I would have to get near a window and find the command that sets off dudes alarm.

There should be local ordinances to control the other issue.

Check out trainfacts.com and email Dale about how to block any interference.