In the last four days, the bulb in the porch light has burned out three times. At first I thought I must have jostled it while painting, but then after replacing the bulb and it burned out again, I noticed that the threaded part of the bulb was quite discolored.

Will replacing this outdoor light fixture likely solve the problem?

Please advise,

D-I-Y

You can replace the socket or lightly sandpaper the socket.

When installing bulbs outside use some petroleum jelly on the threads or dialectric grease.