CNC Touch Blocks are usually made out of metal and are expensive. this is a cheap alternative to create a touch block and coat it with metal tape.

There is an Inch based model that is offset 1/4" in each direction once aluminum tape is added to the top, bottom and sides. the holes are for a 6-32 screw to attach a wire. Tape is .004" thick. most is 1.88" wide but 3" tape will be easier to cover the surface and sides.

Metric touch plate is 5mm offset with aluminum tape .12mm thickness. the hole is for a m3 screw to hold a wire.

Make sure the tape touches each other and the screw where the wire is attached.