So we had a situation where someone cast an illusion and hid in it, then proceeded to cast psychic attacks from within. 

So... Do psychic attacks reveal unseen attackers? RAW says when in doubt, if there is an attack roll, there is an attack therefore, etc. But, psychic attacks don't all have attack rolls. They have verbal commands, but what if you place silence around the targets area? Then they can't hear the rough location of the attacker. Would the attacker remain unseen? My assumption is that attacks, melee, ranged or spell, have a portion of it that is visible or audible or both, and there is no combination that doesn't bring attention to the attacker's location. But Psychic attacks wear the casting can't be heard and the attacker is hidden? Being that the skulker feat has it's reasoning and affects this rule, then the possibility of Psychic attacks not revealing the opponent may be possible? Thoughts?

DId it use an attack roll? then they are revealed, otherwise Dm fiat.

There's a lot here that is missing to properly answer your question.

Assuming minor illusion was cast?  Let's say the caster creates a wall.  Since they cast it, they know the illusion is fake.  They can see through it.  Minor Illusion requires Somatic and Material, but no verbal component.  So it's possible to set this up pretty stealthy.  

As far as the attack itself is concerned, it depends on how the attack takes place.  The caster is standing behind the wall, which they know is fake and can therefore see through it.  Target appears.  Caster makes their move.  Basic Rules/DMG state: When a creature can't see you, you have advantage on attack rolls against it. If you are hidden--both unseen and unheard--when you make an attack, you give away your location when the attack hits or misses.

So it doesn't say the person can see you, but they do know where the attack came from, assuming it required some form of attack roll.  If it requires a save though, it's an entirely different answer. In the PHB it states: "If there's ever any question whether something you're doing counts as an attack, the rule is simple: if you're making an attack roll, you're making an attack."

So if I cast a spell behind that wall, which requires the target to make a saving throw?  Unless something about it tells them that they know my location on the fail?  They don't get to know my location.  Sage advice clarifies this kind of logic when talking about Uncanny Dodge:

Does Uncanny Dodge work automatically against every attack a rogue or ranger gets hit by? Spell attacks too?

A use of Uncanny Dodge works against only one attack, since it expends your reaction, and only if you can see the attacker. It works against attacks of all sorts, including spell attacks, but it is no help against a spell or other effect, such as fireball, that delivers its damage through a saving throw rather than an attack roll

Now, obviously, there are some logical things to this.  If we say the mage behind their illusory wall casts fireball, I'm going to give it to my players that a glowing bead of pure fire came through that wall, take that how you will.  Anyone with a passive investigation higher than the spell save DC would automatically succeed in knowing, anyone who had been around someone with illusion magic would automatically succeed, anyone who remotely asked the question of "That walls fake" would automatically succeed.   

So to answer your final thought, it's not only possible?  Its rules as written.

So mind sliver is not an attack roll. Would your position be given away if you are hidden? It has a V component? I am of the thought that V components can not be whispered.

There's nothing inherently special about "psychic attacks." They are just regular attacks that deal psychic damage, and they follow the same rules as all other attacks.

Remaining undetected during a battle is intentionally very difficult in 5e, probably because it makes for very frustrating, one-sided battles. Even if you are under greater invisibility and cast a spell with no vocal component, the other side notices not only that you're there but also your general position. You need to spend an action to Hide in order to be undetected.

Thank You!

You are right in guessing Minor Illusion. The spell used to attack was Mind Sliver. It has a V component so my assumption was when casting you are no longer unheard and therefore no longer "hidden" or "unseen". But if the V component was mitigated somehow or Metamagic'ed? I would think that would be a work around. Causing of course an unfair situation, but is DnD supposed to be fair or smart? I see it like spades where finding the holes in the rules is fun. But another aspect to being attacked is that fairly speaking, if you  are causing damage to an opponent, you are attacking. That isn't in the rules but feels logical. It is called a psychic attack. Not a psychic experience that causes pain and damage and disorienting but isn't an attack. Thoughts? I also noticed this in the Players Handbook for Mind Sliver.

Quote from Rationale01 >>

You are right in guessing Minor Illusion. The spell used to attack was Mind Sliver. It has a V component so my assumption was when casting you are no longer unheard and therefore no longer "hidden" or "unseen". But if the V component was mitigated somehow or Metamagic'ed? I would think that would be a work around. Causing of course an unfair situation, but is DnD supposed to be fair or smart? I see it like spades where finding the holes in the rules is fun. But another aspect to being attacked is that fairly speaking, if you  are causing damage to an opponent, you are attacking. That isn't in the rules but feels logical. It is called a psychic attack. Not a psychic experience that causes pain and damage and disorienting but isn't an attack. Thoughts? I also noticed this in the Players Handbook for Mind Sliver.

ATTACK/SAVE

INT Save

This makes attacking and saving throws equal as I perceive it. 

 

 

Perception and rules are two different things.  Mind Sliver requiring a save means the person who is on the opposing end does not automatically perceive where they are by nature of the attack rules.  That being said, Mind Sliver DOES require a verbal component like you said, and spells in 5e are described as chanting loudly, specifically so that Sorcerer and Subtle Spell has a distinction and a reason for using it.  If I were the DM there, I would say the sound is coming from the direction of the illusion as to not give away the fact that it might be an illusion.  

That being said, the PHB doesn't have Mind Sliver, it is Tashas.  You are also mistaking how D&D Beyond has chosen to categorize that specific field as being part of the rules.  It's not.  It's there just for a very clean dedicated spot for what type of roll the player/opposing party has to make.  RAW, you don't automatically have knowledge of specifically where the person is in the case of Mind Sliver.  

Thanks!

Unless a game element has an attack roll or is otherwise identified as an attack, It shouldn't count as such. Exceptions like grapple or shove are melee attacks using ability checks instead.

But if it does dmg on a save, isn't that an attack? Casting a spell as an action in combat that does damage is hard to swallow as not being an attack.

Quote from Rationale01 >>

But if it does dmg on a save, isn't that an attack? Casting a spell as an action in combat that does damage is hard to swallow as not being an attack.

 No it is not an attack