Peter Wallace Form 3 Vivint Smart Home / PETER WALLACE ownership change

                               POWER OF ATTORNEY

Know all by these presents that the undersigned, does hereby make, constitute
and appoint each of Alex Dunn, Dale Gerard and Shawn Lindquist, or any one of
them, as a true and lawful attorney-in-fact of the undersigned with full powers
of substitution and revocation, for and in the name, place and stead of the
undersigned (in the undersigned's individual capacity), to execute and deliver
such forms that the undersigned may be required to file with the U.S. Securities
and Exchange Commission as a result of the undersigned's ownership of or
transactions in securities of Mosaic Acquisition Corp. (which expects to change
its name to "Vivint Smart Home, Inc.")  (the "Company") (i) pursuant to Section
16(a) of the Securities Exchange Act of 1934, as amended, including without
limitation, statements on Form 3, Form 4 and Form 5 (including any amendments
thereto) and (ii) in connection with any applications for EDGAR access codes,
including without limitation the Form ID. The Power of Attorney shall remain in
full force and effect until the undersigned is no longer required to file Forms
3, 4 and 5 with regard to his or her ownership of or transactions in securities
of the Company, unless earlier revoked in writing. The undersigned acknowledges
that Alex Dunn, Dale Gerard and Shawn Lindquist are not assuming any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934, as amended.


                                     By: /s/ Peter Wallace
                                         -----------------
                                     Name: Peter Wallace


                                     Date: December 11, 2019