rear window brake light ,any ideas

[brett]

afternonn all got a rear window brake light but it doesnt seem to work properly ,well didnt think it was working at all till looked at it at work last night ,so it does seem to come on but its very faint ,any ideas ,bad connection ,water damage ?
thanks in advance    brett

[brett]

right been on google and seems possible that one of the rear lights could could have the wrong bulb somewhere ,which apparently could cause this ,well hopefully its this and not a new rear light job