Commas with "Perhaps"
Solution 1:
Sometimes, but most of the time you shouldn't. And it depends on the thought of the sentence.
Normally, perhaps would not be needing a comma when it is used at the start of the sentence.
Perhaps you could get me a drink.
Looking at the sentence above, when you omit "perhaps", the sentence would still stand alone and the thought would still be clear as in:
You could get me a drink.
When using "perhaps" mid-sentence, you could omit the commas and the thought would be still clear and whole since, by nature, "perhaps" is an adverb expressing the possibility for something to happen or to be.
You could perhaps get me a drink.
But when you feel that you could use "perhaps" parenthetically (to add information or to help with the thought), you may surround the the word with commas when it is used in the middle of the sentence. This creates a more dynamic sentence as one may read "perhaps" with a slight pause before and after the word, adding an emphasis to the possibility of, in this case, the person getting you a drink, which, as structured in the sentence, can be interpreted as an enticement for someone to buy a drink for them.
You could, perhaps, get me drink.
All in all, it will depend on the temperature and the weight of the idea you're trying to convey. There is no specific rule on this one; you could play with the word and see the effect it has on the entire sentence as long as you follow grammar.