A label for a switch describes a setting that is either on or off — two mutually exclusive states. Use a short description (1-3 words) of the setting. Try to include all necessary information in the label, but it's OK to add clarifying text after to supplement if needed.
Keep in mind that when a user takes an action on a switch, that action will often affect other content in an experience. Think systematically to ensure that all labels are paralleling each other in their writing.
Consider if the label should use a verb or a noun
A switch shows a state of persistence for something — a noun or a proper noun — as either being "on" or "off." A verb isn't usually needed to communicate the thing being turned on or off, but there can be instances where phrasing the label as a verb can aid in clarity. Just try to keep switches consistently using either verbs or nouns if you have more than one of them in a single view.
Avoid using verb phrases related to a state of activity
Avoid using verb phrases related to activity states in a switch label, such as "turn on" or "turn off." A switch is naturally either in a state of being on or off — active or inactive — so repeating in the label that something is "on" or "off" is redundant and clutters an interface.
Use a neutral tone
Because switches are used for controls and utility, their labels are written in a neutral, utilitarian way. There's no need for overly celebratory language.
Use "you" or "your" if needed to refer to the user directly
Describe switches objectively by using only the names of features or settings, or what those features and settings will do. In the case where it's necessary to refer to a user directly, do so sparingly and use the second person "you/your." We aim to be conversational and talk to the user — not as them.
Use sentence case
Following Adobe's UX writing style, labels for switches are written in sentence case unless they contain words that are branded terms.