The vulnerability of consumer products that are developed to integrate a home's wifi system to create a "smart house" have very weak security. For example, thermastats, refigerators, light bulbs, etc. are built for convenience of use at the expense of security.
Here is a recent article written on ZDNet in Feb. 2020 https://www.zdnet.com/article/what-is-the-internet-of-things-everything-you-need-to-know-about-the-iot-right-now/ warning consumers of the low level of security built into these add-ons with many links related articles. I love the title of this article...175,000 IoT cameras can be remotely hacked thanks to flaw, says security researcher: Researchers have found that it's trivial to remotely access one brand of security camera. https://www.zdnet.com/article/175000-iot-cameras-can-be-remotely-hacked-thanks-to-flaw-says-security-researcher/
These articles were found doing a simple google search. Doing a search on Reddit will give you much more detailed information on what products are most vulnerable and how to hack into them. I think you will like these articles as well:-) https://www.ehackingnews.com/2020/06/the-russian-quality-system-roskachestvo.html & https://www.ehackingnews.com/2020/06/hackers-can-now-spy-your-conversations.html