Inserting bi-pin bulbs into candle sockets
Trim the wires of the bi-pin bulb until they fit into the candle socket.
Remove the bulb from the socket, bend the two wires a little bit apart
and kink one wire of the bulb. Put the straight wire of the bulb a little bit
in the socket first and then pivot the bulb until the kinked wire fits
into place. By making a kink in one wire the bulb will stay much firmly
in the socket.
The foregoing is especially important if you want to use a socket with
a bi-pin bulb as a hanging light fixture, so upside down.
Even more important when using a short candle socket as a hanging
light fixture (see the picture below).
To ensure that the bulb is firmly seated into the socket
bend the pins of the bulb a bit apart and kink one wire.
Whatever socket you are going to use depends on the project at hand.