Do I have to have "new" wires when I get spark plugs changed in my 97 Cadi Deville with 65K miles on it?

no it is not necessary to buy plug wires every time, I visually inspect them all for signs of wear and tear anywhere the come near a possible contact point, but if the last mechanic routed them correctly and used the keepers to hold wires apart and nothing is shorted out against a frame, plug wires will last 20 years easy sometimes. I have an original set in an 88 van, Im aware of it the rubber insulation is still rubber not brittle and cracked, and I listen every morning when I start the van. A plug wire that gets dried and cracked can let moisture into the metal core, Which will not spark correctly until several shots of the coil dissipate moisture, so in the morning when cold I fire it up, within a second or two van is hitting on all 8 cylinders I know Im good to go. The sensors are sensitive enough to pick up tune up issues too, and a check engine light will pop on if I have a problem too.

If there's a problem related to the wires then by all means change them. I see the mileage you have on the vehicle is low for the year model. Are you having an engine miss or running problem? The plugs have relatively low miles for a change. Are you just being told you need a tune up or is there a problem? Good luck.

relying on the manufactures advice. The wires will in many cases very last 45K mile previously replacing, the Spark plugs on some want replacing at 12, 18 50 and 100K miles, look contained in the hand e book for the right time to interchange the plugs.

Even car manufacturers do recommend to replace spark plug wires if only to be able to sell these slow moving parts. Technically, these wire doesn't wear that much. For 60K or so miles, if you can spare few bucks, then go for it, for your peace of mind.

Wires last a long time.

So no, unless you thing you have a problem like misfire or engine shake.

It is recommended to change the wires together with new plugs. I have done that on my cars.

They are likely still in good shape unless they have burns or other damages, I would think your plugs are still in pretty good shape too unless it's running crappy.

not necesarily but i would do it