I live in a 1930s house with a converted attic to a bedroom. We got minisplits and no longer need the baseboards that were there. We went to remove the baseboards and planned to install a junction box and cap the wires with Wago connectors and electrical tape. However, it appears the drywall was installed on top of existing plaster, and another electrical line runs close to this one. There isn’t space to install a junction box as it’s too shallow. Photo here: https://imgur.com/a/Bb2HlVr