Your question asks, "Is it legal" which requires an attorney to respond. Professionals understand they can not answer such a question because they are not professionally qualified. Without a doubt there will be citizens and other rogue elements who willl offer advise.
It is really, really important to know if the home is for sale? If yes, and it was allowed it to be published on the itnernet....all control of the data has been lost. Anyone can pretend to sell the home through public deception.. Trulia can. Zillow can.
If the homes street view is available on Google Maps, anyone can pretend to sell your home. ALL homeowners should blur their homes street view on Google Maps. If they don't they wil be guilty of passive consent.
You do not provide information regarding where the 'for sale' was observed or if an agent is involved
Had your question been worded, "Under traditional circumstances, can a home be sold without the owners permission?" the answer would be NO, the home can not be sold under normal circumstances without the consent of all owners. Your question, however is about advertising.
Had your question been, "Can a real esate agent advertise a home for sale without all owners permission?" you will fnd the answer to be yes. Most agents wil realize the futility of such action since the sale can ot occur with consent. There however must be one party in the ownership that give consent to advertise.
Had your question been "Can a REALTOR (R) advertise a home for sale without all owners permission?" the professional code of conduct would say NO! However, in cases of estrangement, exceptions have been made. However, even then, both must agree to complete the sale.
Had your question been, "Don't you think it a really smart ideas to make sure all decision makers are on board before proceeding?" That would get a resounding YES!
You will need to get professional or legal advise regarding what applies in Benwood WVA.
If you are not working with professional representation,....well you're on your own.
Also, if it is a joint tenancy or tenancy in common one of the parties can advertise a sale in the hope of getting the consent of the other parties.
If you are talking about Craigslist, that is an ongoing scam. They advertise a property for a low rent, have the sucker wire the funds saying they will mail the keys.
If you are talking about a Craig's List posting or some other type of advertisement, you need to beware because there is no one overseeing that kind of ad. Make sure that whoever you deal with can show you a copy of a deed and a picture ID so that you have at least some assurance that you are dealing with the rightful owner. Double check in the Maryland property database online to make sure that the owner's name matches.