I was thinking of using these boxes to control switches and signals. I downloaded the instructions and it says to connect them to 194548 base station for power. I don't see the piece as available from the online sites I order from. Is there an alternate or newer way to connect these?

Unless you already have a MyWorld(Hobby) starter set (which you indicate you do not by not having the track adapter), I would go as far as to assertively dissuade the use of these control boxes (and not just because of the cost).

For the turnouts/points (and all NON MyWorld signals) a standard (and cheaper) 72720 or its many equivalents will do.

For the MyWorld(Hobby) Signals you may look at the 60841. This may be bit over the top if you are not going to be using digital control in the near future but it is a long term investment, where as the 7275x options are stunted in there options for future expansion. Failing that a visit to an electronics store for diodes,resistors (and switches) will get you a more useful solution

If you indicate which Controller you currently have and which points/signals you have or plan to get, it would help.

Yes , the signals themselves are quite OK. It is the control/implementation that is the let down.

The devices make use of the LED (Diode) characteristic that allows for only needing 2 wires.
With a +ev voltage on color lights and with a -ev voltage the other one lights.

One possible wiring option....

This is a rudimentary DC variant
Most Marklin modellers have a spare AC transformer and that means tou can use a SPST switch or use the DPDT switch with the other pole controlling the dead section of track



The resistor value (shown as 470 for a 9V Battery) varies with voltage