The TV yes, if it's Chromecast compatible. Install the Built-In Chromecast Integratrion app and make a custom command from RM.
For playing a track, you use this method, but instead of speak, the command you'll choose will be playtrack and enter a path to the file on a local computer. Someone posted that they were able to point to an amazon cloud source, but I cannot find that now. Might have been a differnet context or a different app. I would think most external cloud sources would be authenticated https, and wouldn't work, but I'm not sure about the external options.
Create a RM rule that when the door contact opens, run the custom command.
There is a problem with door chimes and Chromecast to Google Home devices though. The connection disconnects automatically every 5 minutes and that cannot be changed. So when it plays the sound after the 5 minute timeout, there's a pause, then an internal tone from the cast device reconnecting (cannot be disabled on Google Home devices) and then finally your tone. I stopped using it for a door chime personally, because of that.
There are other options that just play a track on a local computer and you connect a speaker to that. Either directly or via Bluetooth connection. One solution is VLC Player on a local computer and the VLCThing driver.
Still another is BigTalker 2.
Many different ways to do this, these are just a few.
