I bought some bare sockets to hold and power my UV heater lamps but the wires came out of the bottom so mounting directly perpendicular to the wall would have been tricky. To solve this I made a small shell for the socket so that it can be taped/glued to a wall and have the wires kept neatly out of the way. Here is the amazon link to the sockets I used.

UPDATE 2020-04-23
Amazon changed the size of the sockets, so I adjusted dimensions to match.