I appreciate this is a tech questions site, and you’ve asked an appropriately on-topic question. However, I believe you’ve asked an XY question and this is actually a parenting problem, not a tech one.
Disabling or blocking your WiFi does not address the root cause of your problem which, reading between the lines, is that you’ve told your kids no internet after 10, but they disregard you. Confiscating devices, banning themdevices from bedrooms, and just making sure your kids respect you enough to follow your wishes/commands might all be better solutions. You might want to look for similar questions (or ask a new one) on Parenting SE.