As long as it has a row source, the default behaviour of a combobox is autocomplete, which is what you're asking for in one part of your post. However, you are also intermingling 'listbox' and 'textbox' in your post, and they do not possess this feature by default. Since a textbox cannot hold a list, I won't address that one further. To create this for a listbox would require you to requery the listbox upon each character being typed into a textbox. The event for the textbox would be On_Change and the call could be as simple as Me.MyListbox.Requery. The underlying query for the listbox would have to use the LIKE operator for the field you're going to search on because most of the time there would not be an exact match.
Here's a link that describes one way to accomplish it, but it's more centered around a continuous form or datasheet. http://allenbrowne.com/AppFindAsUType.html
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.