No, it probably wasn't wrong for you to allow your son to return home until he found a job. After all, your motives were right; you were only trying to help him.
But it was wrong for you to let it go on indefinitely -- particularly when it became clear that he was only taking advantage of you and had no intention of finding a job. And from what you say, this situation probably isn't going to change; in fact, it may only get worse as he falls further into a pattern of irresponsible living. The Bible bluntly says, "If a man will not work, he shall not eat" (2 Thessalonians 3:10).
Not only are you inconveniencing yourselves, but you're actually hurting your son by allowing this to continue. God doesn't want him to waste his life -- but that could easily happen if nothing changes. Even if jobs are difficult to find in your area, he should at least be looking -- and helping around the house.
It may not be easy, but you need to talk frankly with your son and together set some specific targets for him to meet. More than that, pray for him and encourage him to seek God's will for his life. God loves him, and He has a perfect plan for your son's life. God's promise is true: "I will instruct you and teach you in the way you should go" (Psalm 32:8).