An atheist and a wiccan no, an agnostic and a wiccan maybe. There are different ways of being agnostic.

Anyone can be agnostic in their belief system.

Being Wiccan and agnostic are completely compatible in my view.

You're correct at least according to the definitions I read.

You are correct.

The five points of the pentagram are often associated elements in the universe: Earth, Air, Fire, Water, and Spirit. ... I would say the spirit point leans it in a religios direction but they do not pray to a god or creator so on that sense it is not. What’s important is that they are not trying to make police or put in schools.. I’m not against people having personal beliefs that do not infringe on my rights.

You are not wrong.

You can practice anything and still be agnostic. Agnostic simply means that you don't know or claim to know the veracity of the existence of god[s]. Many people make all kinds of decisions in their lives without knowing for sure.
To put it another way, if you're driving down the road and come to a fork, how likely are you to stop and evaluate vs a real quick eenie, meenie, miney, fuck it..? An agnostic who practices Wicca (or any other religion) is simply one who decided that [s]he would not let not knowing get in the way of trying.

Having dabbled in Wicca and having friends that are Buddhist, Hindu, Christian, Jehova's Witness, Wiccan, Agnostic,Atheist and just plain spiritual(which is not plain at all.) I think labels can tend cause far more problems then they solve. Wiccan me is a set of ideas and tools for a very personal connection with the idea that the earth is divine. Many see the earth as a Goddess. Others maybe as a primal force. When people start telling other people the way they should worship/connect etc that I think is were things go south. Can you be wiccan and agnostic? Lets break it down. Agnostic according to the urban dictionary; A person who is sensible enough to admit that they have no fucking clue what is going on in the universe.

Contrary to both a Theist (someone who sits in Church thinking they have shit figured out) and an Atheist (someone who sits at Starbucks thinking they have shit figured out).

Wiccan: A Wiccan is a member of the Pagan-Revivalist religion known as Wicca. Can be a male or female practitioner or lay-follower, either solitarily (on their own) or members of a Coven (group). See Wicca for more details on the religion and its practices.

Now right off the bat I think cause I like to challenge very nearly anything- Who get to decide what a wiccan is? The wiccan pope? The reason I like wicca is for its more personal nature and non judgment. And yet like any organized human group there are always people who are like, "Your doing it wrong!" I hate that.

My point would be does this person walk the Wiccan walk? Do they belong and cooperate and get along with other wiccans even if there are just 3 of them? or 50? Then cool. Can they be a wicca of one? Why not? Me I am a faith of one. I do not need anyone else to tell me I am doing it right or wrong. Maybe when I die some version of the ever after will fill me in. I am looking forward to finding out!

So why not, can this person find value in the practice of Wicca and yet also realize they can never be sure about the nature of the universe and the question of if the goddess really exists? Maybe they simply use Wicca as a tool for self awareness and a connection to a greater truth not defined by a name or a image. What is the harm in that?

Wicca, for me, (when I practiced years ago) was more about self worship and/or empowerment, as well as the appreciation and love of nature. Being thankful to the earth, so on and so forth. It also had a very simple rede, "ye harm none, do what ye will". It is what you make of it really. SOME people treat it, and practice it differently, but ultimately, yes, you can still be agnostic.

While many practitioners of Wicca choose a certain pantheon -- Norse, Celtic, Roman, Greek, Egyptian, etc -- as their figurehead goddesses and gods to whom they direct their rituals and prayers....these are more archetypes and representative of the various forces of Nature.

There is no centralized authority of Wicca nor are there specific goddesses and gods. Centerpoint to the religion is a worship of "Mother Nature/Mother Earth" in Goddess form.....and all other goddesses & gods are invoked only as tradition or by choice with no real belief per se in that there is a supernatural deity up in the heavens.

So, yes, a Wiccan Agnostic is not unreasonable nor impossible. In fact, I would venture that it is the norm.

Maybe they're practicing being wiccan for fun, but not sure if the deity behind it is actually real.