It is very possible to find an expired domain. You just need to go for a list of justdropped expired domain because they are much cheaper to get in auctions.

What do we refer to as expired domain business

First and foremost, we will be defining an expired domain. An expired domain is a domain name that previously points to an IP address, but doesn't anymore. I hope you understand this.

If you put an expired domain on your browser and search for it, the domain name system (DNS) won't be able to connect to an IP address and because of that, the domain won't open.

Buying and selling of domain is very lucrative.

Can I buy an expired domain name?

Yes, you can, because nobody owns a domain name. Buying domain name from sites like wealthy affiliate, bluehost etc. Only means you are lease-ing it, and it doesn't belong to you fully. It's like renting a house, you can always use it for a specific period, and when you fail to renew it at the appropriate time, you run the risk of losing it. A domain name can be leased only for a period of 1-10 years. Failure to renew it after its expiration period will make it to be leased to another person interested in it. Most of the times you are being given a good period of one month.