A reminder that cordless home phones don’t work with no grid power so corded backup is a good idea. It’s also helpful in troubleshooting phone problems at home. A Telephone Butt Set is better, more on that later. The grey box on the side of your house is called the NID (stands for network interface device, I think) and the NID ususally has a phone jack in it and a short jumper in this jack that is wired to the house phones. If you house phones don’t work you can plug your $10 Walmart corded phone into the NID jack to determine where the problem is, or to make a call. If you house wiring has a short, open or is mouse chewed then connecting at the NID will bypass the bad wiring and you will have one wired phone connected straight out to TELCO.
You can do the same with a Telephone Test Set, also called a Butt Set. I think the name Butt Set comes from the fact that you can clip onto a line in use and butt in to the conversation. 
This is the ruggedized telephone with red and black test leads and alligator clips that you see that phone repairmen using. The alligator clip ends have 2 variations. One is a single spike within the jaws and the other is a Bed of Nails. This is a circle of small spikes and a flat anvil that, when clipped on a solid insulated phone wire will pierce the insulation and make an electrical connnection. It saves stripping wires just to check for dial tone. These butt sets are expensive but available on ebay and elswhere and good to have. The following is for information only, this is NOT an instruction or recommendation. With a butt set you can test for dial tone, or make a call from your house wiring, from the NID, from the telephone terminal at the street (BIG EMERGENCY ONLY). Note that clipping on your neighbors line at the street terminal will put the call on their bill and make their caller ID appear on the other end. ANYTHING OTHER THAN CHECKING YOUR HOME LINES AND YOUR NID IS OF QUESTIONABLE LEGALITY. USE YOUR BRAIN.
