EXHIBIT 24

                                  POWER OF ATTORNEY

        With respect to holdings of and transactions in securities issued by
Starry Group Holdings, Inc. (the "Company"), the undersigned hereby constitutes
and appoints the individuals named on Schedule A attached hereto and as may be
amended from time to time, or any of them signing singly, with full power of
substitution and resubstitution, to act as the undersigned's true and lawful
attorney-in-fact to:

        1.  execute for and on behalf of the undersigned, Schedules 13D and
              13G in accordance with Section 13 of the Securities Exchange Act
              of 1934, as amended (the "Exchange Act"), and the rules
              thereunder, and Forms 3, 4, and 5 in accordance with Section 16
              of the Exchange Act and the rules thereunder;

        2.  do and perform any and all acts for and on behalf of the
              undersigned which may be necessary or desirable to complete and
              execute any such Schedule 13D or 13G or Form 3, 4, or 5, complete
              and execute any amendment or amendments thereto, and timely file
              such schedule or form with the SEC and any stock exchange or
              similar authority; and

        3.  take any other action of any type whatsoever in connection with
              the foregoing which, in the opinion of such attorney-in-fact, may
              be of benefit to, in the best interest of, or legally required
              by, the undersigned, it being understood that the documents
              executed by such attorney-in-fact on behalf of the undersigned
              pursuant to this Power of Attorney shall be in such form and
              shall contain such terms and conditions as such attorney-in-fact
              may approve in such attorney-in-fact's discretion.

    The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform any and every act and thing whatsoever requisite,
necessary, or proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as the undersigned might
or could do if personally present, with full power of substitution and
resubstitution or revocation, hereby ratifying and confirming all that such
attorney-in-fact, or such attorneys-in-fact substitute or substitutes, shall
lawfully do or cause to be done by virtue of this Power of Attorney and the
rights and powers herein granted.

        The undersigned acknowledges that the foregoing attorneys-in-fact, in
serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to
comply with Section 13 and Section 16 of the Exchange Act.

        This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Schedule 13D and 13G and Forms 3, 4,
and 5 with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the undersigned in
a signed writing delivered to the foregoing attorneys-in-fact.

   IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 28th day of March, 2022

                                   /s/ Alex Moulle-Berteaux
                                   -------------------------------
                                   Name: Alex Moulle-Berteaux


                                Schedule A

        Individuals Appointed as Attorney-in-Fact with Full Power of
Substitution and Resubstitution

1. Chaitanya Kanojia
2. Komal Misra
3. William Lundregan
4. Brian Regan