NOTE: This article also applies to the Wemo Mini and Wemo Bridge.
Step 1: Launch the Wemo app.
Step 2: Tap Rules.
Step 2: Tap Rules.

Step 3: Tap a Currently Active rule under the ENABLED RULES.

Step 4: On the upper-right corner, tap on Disable.

Step 5: Tap < Back to return to the Rules tab.

You should now have successfully disabled a rule on your Wemo app. Additionally, you may choose to Delete a rule to avoid conflicts with the Apple Home app. To learn how, click here.
Related Article:
Getting to know the Wemo Rules