We claim the ornamental design for an electric heater and humidifier device, as shown and described.
FIG. 1 is a perspective view of an electric heater and humidifier device, showing our new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a bottom plan view thereof.
The broken lines in the drawings show portions of the electric heater and humidifier device which form no part of the claimed design. Words, numbers, characters, and symbols shown in broken lines within a display screen portion disposed on the top side of the device do not form a part of the claimed design.