Put together a privacy and security presentation.

Does your family use password managers? (And dear god not Lastpass, with their breech a couple years ago).

What do your parents do if one is incapacitated? The self-hosting community has discussions on managing this.

This is a great opportunity for you to learn a lot of stuff and show your parents how to approach security and privacy.

Start with understanding their needs... Truly understanding, take your time. Solutions can always be found later, once the requirements are well understood.

As an aside, as someone likely old enough to be your grandparent, I can't imagine needing an intercom in a house. Some of my family had them growing up, and found it to be not nearly as useful as they thought it would be.

Use a hammer to turn it off. Or spray it full of expanding foam