If you wrote an answer that you found to be wrong, you could edit it to make it correct; in the case there is another answer, and your answer would become too similar to the existing one, then you can delete it. In this case, deleting it (if editing is not worth doing it) would avoid that future users, seeing it has a score of 3 (as it actually has), would think the answer is correct.
If you provide links to different resources or you quote different resources, then I would think it's worth editing it. If the text would be too similar even in this case, I would delete it.
Don't edit the answer to replace its text with a placeholder, such as "This is not longer applicable." or "Wrong answer." If you keep doing it for your answer, this would be considered vandalism of own posts. At least, it would be flagged as "not an answer," and moderators could do one of the following actions:
- Delete your answer.
- Revert the post to the last revision.
Between the two, it's not said the first is the preferred one, especially if moderators notice you have recently edited your post.
The other reason I would not do it is that your post could attire down-votes.