I made this relay bank as part of a thermostat system for the HVAC systems where I work.  As such I made the labels correspond to the heating and cooling levels, but I also made a generic version that just labels it 1-4.  The design features windows so that you can view which relays are active, holes for ventilation and holes for wire connections.  The two halves of the enclosure should snap together and release by pressing the side buttons.

It works with relays like these:

https://www.amazon.com/dp/B095YD3732?ref=nb_sb_ss_w_as-reorder-t1_k0_1_6&=&crid=1GHDEF0THG7AO&=&sprefix=5v+rel

Of course, anything similar will work too.

I made this design using Solidworks.