Reproduction steps:
1. Open the attached project "1222750.zip"
2. Open the Sample Scene
3. Enter Play mode
4. Click anywhere on the Game window with a touchscreen monitor

Expected result: Nothing is logged as there are no Touch bindings for the PrimaryTouchPressed Input Action
Actual result: "Primary touch pressed" is logged

Reproduces on: Input System 1.0.0-preview.5 (2019.3.3f1, 2020.1.0a25)

Notes:
The behaviour of a mouse click and a touchscreen touch is inconsistent as InputAction phase Started will only be triggered when touch ends or is dragged.
Reproduced on Dell P2418HT, the user was also able to reproduce on Acer T232HL and Cintiq Pro 32.
Input System is not available on Unity 2018.4 and below, therefore, the issue is not reproducible.
Could not reproduce on Unity 2020.2.0a25 with Input System 1.0.0-preview.5 due to the issue 1222750.
The reproduction project does not work on Input System 1.0.0-preview.4 and below.