The ornamental design for an "telephone handset", as shown and described.
FIG. 1 is a top, front, and left side perspective view of said "telephone
handset" showing my new design, wherein the dotted line material is for
reference purposes only and forms no part of the claimed invention;
FIG. 2 is a right side elevational view of my new design, wherein the
dotted line material is for reference purposes only and forms no part of
the claimed invention; and,
FIG. 3 is a rear elevational view thereof, wherein the dotted line material
is for reference purposes only and forms no part of the claimed invention.