I was contacted by a company and asked to come for an interview tomorrow morning. But later after I scheduled an interview with them, I found that I didn't even apply to them. I also found a lot of bad reviews about this company online. Many people mentioned that they also got a call without applying to this company and how this job is actually a door-to-door sales job. It sounded like a scam to me now. So what should I do? Should I still go to that interview tomorrow as scheduled or send them an email to cancel the interview?
You are in no way obligated to put yourself at risk - or even just waste your time - on a scam, or any other similar shady operation such as this. You'd be maximally polite to even email them to cancel - a lot of people would skip that. But yes, certainly cancel instead of going.
I've ended up actually attending interviews such as this, in my case I was invited and they didn't pretend I applied, and I spent most of my time trying not to roll my eyes while they told me what a "smart guy" I was, and how I could have unlimited income potential selling people insurance "across the kitchen table" (the product itself was, of course, junk). It was a rather infuriating waste of an hour.
When you don't go they will likely initially try to convince you what a great opportunity this is, and make some weird passive aggressive jabs or guilt trip to try to get you to reschedule - don't do that either. They'll eventually rationalize to themselves that "some people just aren't dedicated/smart/non-brainwashed enough to want to be financially independent", and they'll move on to trying to shake down some other desperate soul. You won't be able to talk them out of it, either.
So really, save yourself the trouble - cancel politely (no excuse, just "I'm not interested in this position, thank you"), ignore any replies, and go on with your life.