If your 7 year old keeps peeing he may have an overactive bladder or may just be drinking too much.
Since you said your 7 year old son is peeing his pants then he may be developing a bladder infection or developing urinary incontinence and should see a doctor and get tested to rule out any health issues.
In the meant time if he's peeing his pants it would be best to have him wear a diaper to manage the wetting and to keep his pants and clothes dry.
A 7 year old boy peeing his pants occasionally is normal and nothing to worry about.
That is unless the 7 year old boy continues peeing his pants often then it can be a cause for concern.
Sometimes a 7 year old boy may be too busy doing something and not want to be interrupted to go to the toilet and so they pee their pants.
And sometimes the 7 year old boy may be afraid to go into public toilets such as at school and so he may then pee his pants then as well.
However if your 7 year old boy is peeing his pants all the time or most of all the time at home or when away from home then he may have a bladder infection or may be partially incontinent.
Or if the 7 year old boy is unable to make it to the toilet at all before peeing his pants then he may be fully incontinent.
Incontinence can happen to anyone of any age.
It would be best to take your 7 year old boy to the doctor to make sure nothing is wrong.
I would recommend though that if your 7 year old boy is having accidents and peeing his pants often that he wear a diaper such as Gentle Steps size 7 diapers.
Dollar General sells an almost plain white diaper in size 7 that is called Gentle Steps that work great for bed wetting in older kids as well as for older kids who are incontinent or having accidents.