Can a spirit die?

God destroys wicked spirits in the lake of fire.

Its called "the second (spiritual) death."

Revelation 21:8 KJV — But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death.

Revelation 2:11 KJV — He that hath an ear, let him hear what the Spirit saith unto the churches; He that overcometh shall not be hurt of the second death.

Angelic spirits and people exist forever.  Some suffer eternal and conscious death in hell.

Every case of like when someone has pooped their beds it's because they're terrorized because there's a demon about them

NO. All Spirits are IMMORTAL.

There's no such things as spirits, so they can't be alive in the first place.  It's an meaningless fictional concept.