Waiting lists are operated by the Public Housing Agency (or housing authority) that manages the Section 8 HCV program. Sometimes a local agency will partner with a housing authority, and operate the HCV program and its waiting list on behalf of the housing authority.
You can only apply to a waiting list if it's open for application submissions. Housing authorities open and close waiting lists for application submissions periodically. A waiting list may be open for a single day, or for several years. Usually, waiting lists are open for more than one day.
Use the search bar here to search for your city, county, or state. Open waiting lists will appear in the Waiting List Openings section of those pages.
Housing authorities are required by HUD to release a public notice announcing the waiting list opening. It's beneficial to know how announcements are made, especially if there's no website to visit. Contact a housing authority, or visit its website to find out how it announces waiting list openings.