Ghost Patron

Originally found on Reddit on a post by u/cat-i-on and edited and updated by me.

Paranormal Activity

At 1st level, you learn the Thaumaturgy cantrip, which counts as a warlock cantrip for you.  If you already know Thaumaturgy, choose a different cantrip to learn from the warlock spell list.  When you cast Thaumaturgy, you can also cause unattended objects (must be tiny or small) in range to harmlessly fly up to 10 feet and/or organize themselves into impossibly balanced stacks.
Additionally, undead have difficulty harming you, instead thinking you own of their own.  If an undead targets you directly with an attack or a harmful spell, that creature must make a Wisdom saving throw against your spell save DC (an undead needn’t make the save when it includes you in an area effect, such as the explosion of fireball).  On a failed save, the creature must choose a new target or forfeit targeting someone instead of you, potentially wasting the attack or spell.  On a successful save, the creature is immune to this effect for 24 hours.  An undead is also immune to this effect for 24 hours if you target it with an attack or a harmful spell.

Ghost Expanded Spells

The ghost lets you choose from an expanded list of spells when you learn a warlock spell. The following spells are added to the warlock spell list for you.

Spell Level	Spells
1st	False Life, Faerie Fire
2nd	Spiritual Weapon, Pass Without Trace
3rd	Nondetection, Life Transference
4th	Greater Invisibility, Death Ward
5th	Wall of Force, Telekinesis

Memento Mori

Starting at 1st level, you gain extra benefits so long as your arcane focus is on your person.  If it is in an extradimensional space, such as a bag of holding, or is otherwise inaccessible to you, you do not gain the following benefits.  If you later replace your arcane focus, you can use that to fulfill the requirements set here instead.
You gain an extra Pact Magic Slot at 1st and 6th levels.
At 14th level, you gain the ability to refresh one of your Mystic Arcanum spell slots as a bonus action on your turn.  The spell slot refreshed can be up to one level lower than the maximum you can cast.
Additionally, you can add your Charisma modifier to your AC so long as your arcane focus is on your person.
If Warlock is the first class you take, you must take or purchase an arcane focus as part of your starting equipment.

Medium

Beginning at 6th level, you gain resistance to Psychic Damage.
You can also communicate telepathically with any creature of the Undead type within 60 ft. of you whether or not you share a language or if they have one.  If they have no language, or are otherwise unintelligent, you can only convey simple concepts otherwise you can communicate as normal.

Spirit Control

When you reach 10th level, your ghostly patron grants you some measure of control over the spells you cast.  You gain Sorcery Points equal to half your Warlock level as well as two metamagic options chosen from those available to a Sorcerer.  If you have Sorcery Points and/or metamagic abilities from a different source, these stack.  You do not gain the ability to convert Pact Magic spell slots into Sorcery Points unless you are also a 3rd or higher level Sorcerer.
In addition, you age at a slower rate.  For every 10 years that pass, your body ages only 1 year, and you are immune to being magically aged.

Scorn the Earth

You gain a fly speed equal to your base land speed and can hover.
You can also move to and from the Ethereal Plane as an action, taking with up a number of willing creatures within 30ft. equal to your Charisma modifier.  While in the Ethereal plane, any creature that you brought along can go wherever they please, but they will need your help to leave unless they have some other means of planar travel.  While you can remain within the Ethereal Plane indefinitely, you can only shift between realms a number of times equal to your proficiency bonus and regain all uses after a long rest.