Internet/Network Security/Paying bills
Is it safer to pay bills by postal mail or online?
You're not going to like this answer, but it's neither-there is risk no matter what you do. Paying bills online is very convenient and can be moderately safe if done correctly.
Some of the basic things you should make your "rules" for doing anything anything online considered sensitive are:
1. Do your important stuff over your own wifi or a mobile data offered by your cell phone provider
2. make sure your wifi is secured-at this point. Lots of router offer security features. I would recommend getting a router that offers a "guest network" and you can put all of your devices on the private side of your wifi network. This split allows you to have a network you keep to yourself without eavesdroppers, and still offer wifi to guests.
You should also enable WPA encryption, mac address filtering, and appropriate firewall rules(or port forwarding to fake addresses)-more info on how to do this can be found by googling your router type
3. use https for sensitive transactions! By now, all of the sites you use to access your finances should offer or even enforce HTTPS, which, in plain terms garbles your data you are sending to a web site so eavesdroppers have a hard time making any sense of it. You will know if a site uses https if the web address starts with https://.
Some online services like gmail even offer an option to always force the use of https!
Overall the web can be scary and even given our best efforts bad things can happen just as in "Real life"